A278342 Zero terms of A278341.

1, 2, 3, 4, 5, 7, 32, 52, 55, 56, 58, 61, 64, 66, 72, 80, 86, 88, 89, 94, 101, 103, 108, 109, 128, 130, 131, 161, 173, 187, 193, 194, 213, 214, 224, 244, 253, 260, 270, 292, 304, 314, 323, 334, 344, 348, 349, 365, 370, 373, 388, 404, 424, 454, 470, 478, 482

Offset: 1

Author

Lei Zhou, Nov 18 2016

Keywords

• nonn
• fini
• full

Comments

It is conjectured that this sequence is finite and all 208 terms are found.

Examples

			A278341(1,2,3,4,5,7)=0, so a(1)=1, a(2)=2,...,a(5)=5, and a(6)=7.
a(7)=32 is because 32 cannot be decomposited into the sum of two terms in A274987={3, 5, 7, 11, 13, 17, 23, 31, 37, 53, 59, 61, 73, 79, 83, 89, 101, 103, 109...}.
		

Links

• Lei Zhou, Table of n, a(n) for n = 1..208

Crossrefs

Cf. A278341, A274987.

Programs

Mathematica

p = 3; sp = {p}; m = 0; Table[
While[m++; l = Length[sp];
  While[sp[[l]] < m,
   While[p = NextPrime[p];
    cp = 2*3^(Floor[Log[3, 2*p - 1]]) - p; ! PrimeQ[cp]];
   AppendTo[sp, p]; l++]; c = 2 - Mod[m + 1, 2]; ct = 0;
  Do[If[MemberQ[sp, m - c*sp[[i]]],
    If[Abs[Floor[Log[3, 2*sp[[i]] - 1]] -
        Floor[Log[3, 2*(m - c*sp[[i]]) - 1]]] <= 1,
     If[c == 1, If[(2*sp[[i]]) <= m, ct++], ct++]]], {i, 1, l}];
  ct > 0];
m, {n, 1, 208}]