S000307


Factors used in forming the lower twin primes in S000305.

2, 2, 5, 3, 9, 6, 43, 18, 41, 82, 63, 47, 64, 108, 41, 192, 150, 91, 15, 5, 20, 214, 218, 46, 180, 121, 31, 80, 115, 39, 88, 2, 384, 1828, 1219, 360, 113, 2, 1111, 559, 687, 26, 1000, 368, 3130, 1198, 1731, 1752, 1240, 1237, 131, 814, 2349, 949, 64, 284, 361

1

S000307

The number a(n) gives approximately the growth ratio for terms in S000305.

T. D. Noe, Plot of 200 terms

T. D. Noe, Table of 200 terms

Eric W. Weisstein, MathWorld: Twin Primes

(Mma) p = 3; Table[k = 2; While[! (PrimeQ[k*p - 1] && PrimeQ[k*p + 1]), k++]; p = k*p; k, {20}]

Cf. S000305, A036014 (similar).

nonn

T. D. Noe, Oct 20 2014

© Tony D Noe 2014-2015