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A109136 Even numbers that are not congruent to 1 mod 3 nor are squares nor are the sum of a prime and a square of a prime. 1
2, 8, 18, 24, 74, 170, 614, 704, 1010, 1164, 15054, 21774, 24476 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

We conjecture that every sufficiently large even number is congruent to 1 mod 3, or is a square, or is a sum of a prime and a square of a prime. The numbers listed here are believed to be the only exceptions. This has been verified up to 100000000.

LINKS

Table of n, a(n) for n=1..13.

MATHEMATICA

okQ[n_]:=Mod[n, 3]!=1&&!IntegerQ[Sqrt[n]]&&Count[n-Prime[Range[ PrimePi[n]]], _?(PrimeQ[Sqrt[#]]&)]==0; Select[Range[0, 25000, 2], okQ] (* Harvey P. Dale, Nov 08 2012 *)

CROSSREFS

Sequence in context: A320662 A171613 A306394 * A295522 A065131 A192157

Adjacent sequences:  A109133 A109134 A109135 * A109137 A109138 A109139

KEYWORD

nonn

AUTHOR

Dmytro Taranovsky (dmytro(AT)mit.edu), Aug 17 2005

STATUS

approved

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Last modified May 24 18:34 EDT 2019. Contains 323534 sequences. (Running on oeis4.)