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A228491 Numbers k for which sum(first k primes) = 3*prime(m) for some m. 1
10, 16, 18, 28, 32, 34, 36, 44, 46, 54, 82, 136, 138, 246, 250, 276, 286, 362, 370, 378, 390, 554, 570, 586, 588, 668, 678, 684, 688, 690, 726, 766, 770, 826, 856, 860, 878, 880, 888, 924, 928, 932, 956, 962, 1048, 1160, 1174, 1210, 1264, 1286, 1292, 1506 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..52.

EXAMPLE

a(1) = 10 because 2 + 3 + 5 + ... + 29 = 3*prime(14) and p(10) = 29 is the least such prime summand.

MATHEMATICA

z = 2800; f[n_] := Sum[Prime[k], {k, 1, n}]; p[n_] := If[PrimeQ[f[n]/3], 1, 0]; t = Table[p[n], {n, 1, z}]; Flatten[Position[t, 1]]

CROSSREFS

Cf. A013916, A228490.

Sequence in context: A192221 A106695 A053747 * A295667 A241763 A233579

Adjacent sequences:  A228488 A228489 A228490 * A228492 A228493 A228494

KEYWORD

nonn

AUTHOR

Clark Kimberling, Oct 01 2013

STATUS

approved

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Last modified May 22 21:05 EDT 2019. Contains 323503 sequences. (Running on oeis4.)