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A278342
Zero terms of A278341
2
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
1,2
COMMENTS
It is conjectured that this sequence is finite and all 208 terms are found.
EXAMPLE
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...}.
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}]
CROSSREFS
Sequence in context: A063738 A063737 A338121 * A276522 A135709 A263043
KEYWORD
nonn,fini,full
AUTHOR
Lei Zhou, Nov 18 2016
STATUS
approved