A335303 Numbers k such that k divides sum of k-th twin prime pair.

1, 2, 3, 4, 5, 6, 8, 12, 18, 30, 60, 70, 78, 150, 220, 240, 340, 360, 396, 672, 840, 1188, 1365, 1665, 3080, 3770, 6420, 7317, 9952, 10356, 12972, 18318, 19218, 20544, 21996, 24750, 28656, 34543, 37449, 41910, 180622, 201570, 245115, 728028, 856420, 897022, 986794

Offset

1,2

Links

Table of n, a(n) for n=1..47.

Chris K. Caldwell and G. L. Honaker, Jr., Prime Curio for 34543

Example

8 is a term because sum of 8th twin prime pair is 71 + 73 = 8*18.

Mathematica

l={}; c=0; Do[If[PrimeQ[Prime[n]+2], c=c+1; If[IntegerQ[(2*Prime[n]+2)/c], AppendTo[l, c]]] , {n, 2, 10000}]; l

Prog

(PARI) is(n) = {!bittest(n, 0)&&isprime(n\2-1)&&isprime(n\2+1)}; \\ A054735
lista(nn) = {my(nb=0); for (n=1, nn, if (is(n), nb++; if ((n % nb) == 0, print1(nb, ", ")); ); ); } \\ Michel Marcus, Jun 01 2020

Crossrefs

Cf. A001097, A001359, A006512, A054735, A077800, A335304.

Sequence in context: A060322 A143285 A346077 * A337448 A019532 A008537

Adjacent sequences: A335300 A335301 A335302 * A335304 A335305 A335306

Keyword

nonn

Author

Metin Sariyar, May 31 2020

Status

approved