Il existe 2 périodes de 39 chiffres pour n/79 en base 2.

Pour toutes les fractions de n/79 en base 2, la période de 1/79 revient alors 39 fois (en orange)

1/79=0,000000110011110110010001110100101010001...

2/79=0,000001100111101100100011101001010100010...

3/79=0,000010011011100010110101011101111110011...

4/79=0,000011001111011001000111010010101000100...

5/79=0,000100000011001111011001000111010010101...

6/79=0,000100110111000101101010111011111100110...

7/79=0,000101101010111011111100110000100110111...

8/79=0,000110011110110010001110100101010001000...

9/79=0,000111010010101000100000011001111011001...

10/79=0,001000000110011110110010001110100101010...

11/79=0,001000111010010101000100000011001111011...

12/79=0,001001101110001011010101110111111001100...

13/79=0,001010100010000001100111101100100011101...

14/79=0,001011010101110111111001100001001101110...

15/79=0,001100001001101110001011010101110111111...

16/79=0,001100111101100100011101001010100010000...

17/79=0,001101110001011010101110111111001100001...

18/79=0,001110100101010001000000110011110110010...

19/79=0,001111011001000111010010101000100000011...

20/79=0,010000001100111101100100011101001010100...

21/79=0,010001000000110011110110010001110100101...

22/79=0,010001110100101010001000000110011110110...

23/79=0,010010101000100000011001111011001000111...

24/79=0,010011011100010110101011101111110011000...

25/79=0,010100010000001100111101100100011101001...

26/79=0,010101000100000011001111011001000111010...

27/79=0,010101110111111001100001001101110001011...

28/79=0,010110101011101111110011000010011011100...

29/79=0,010111011111100110000100110111000101101...

30/79=0,011000010011011100010110101011101111110...

31/79=0,011001000111010010101000100000011001111...

32/79=0,011001111011001000111010010101000100000...

33/79=0,011010101110111111001100001001101110001...

34/79=0,011011100010110101011101111110011000010...

35/79=0,011100010110101011101111110011000010011...

36/79=0,011101001010100010000001100111101100100...

37/79=0,011101111110011000010011011100010110101...

38/79=0,011110110010001110100101010001000000110...

39/79=0,011111100110000100110111000101101010111...

40/79=0,100000011001111011001000111010010101000...

41/79=0,100001001101110001011010101110111111001...

42/79=0,100010000001100111101100100011101001010...

43/79=0,100010110101011101111110011000010011011...

44/79=0,100011101001010100010000001100111101100...

45/79=0,100100011101001010100010000001100111101...

46/79=0,100101010001000000110011110110010001110...

47/79=0,100110000100110111000101101010111011111...

48/79=0,100110111000101101010111011111100110000...

49/79=0,100111101100100011101001010100010000001...

50/79=0,101000100000011001111011001000111010010...

51/79=0,101001010100010000001100111101100100011...

52/79=0,101010001000000110011110110010001110100...

53/79=0,101010111011111100110000100110111000101...

54/79=0,101011101111110011000010011011100010110...

55/79=0,101100100011101001010100010000001100111...

56/79=0,101101010111011111100110000100110111000...

57/79=0,101110001011010101110111111001100001001...

58/79=0,101110111111001100001001101110001011010...

59/79=0,101111110011000010011011100010110101011...

60/79=0,110000100110111000101101010111011111100...

61/79=0,110001011010101110111111001100001001101...

62/79=0,110010001110100101010001000000110011110...

63/79=0,110011000010011011100010110101011101111...

64/79=0,110011110110010001110100101010001000000...

65/79=0,110100101010001000000110011110110010001...

66/79=0,110101011101111110011000010011011100010...

67/79=0,110110010001110100101010001000000110011...

68/79=0,110111000101101010111011111100110000100...

69/79=0,110111111001100001001101110001011010101...

70/79=0,111000101101010111011111100110000100110...

71/79=0,111001100001001101110001011010101110111...

72/79=0,111010010101000100000011001111011001000...

73/79=0,111011001000111010010101000100000011001...

74/79=0,111011111100110000100110111000101101010...

75/79=0,111100110000100110111000101101010111011...

76/79=0,111101100100011101001010100010000001100...

77/79=0,111110011000010011011100010110101011101...

78/79=0,111111001100001001101110001011010101110...

On remarque que le produit du nombre de périodes (2) et de leurs longueurs (39) est égal à 78 et donc au premier -1.