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A023870 a(n) = s(1)t(n)+s(2)t(n-1)+...+s(k)t(n+1-k), where k=[ (n+1)/2 ], s = (natural numbers), t = (primes). 1
2, 3, 11, 17, 40, 56, 104, 136, 219, 265, 397, 475, 672, 776, 1046, 1198, 1561, 1755, 2223, 2443, 3026, 3316, 4030, 4352, 5215, 5605, 6631, 7119, 8318, 8878, 10270, 10892, 12499, 13183, 15019, 15847, 17930, 18836, 21182, 22210, 24837, 26039, 28965, 30267, 33504 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

COMMENTS

Also, a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n-k+1), where k = [ n/2 ], s = (natural numbers), t = (1, p(1), p(2), ... ).

CROSSREFS

Sequence in context: A176671 A191085 A024859 * A025099 A024597 A147655

Adjacent sequences:  A023867 A023868 A023869 * A023871 A023872 A023873

KEYWORD

nonn

AUTHOR

Clark Kimberling (ck6(AT)evansville.edu)

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Last modified February 15 07:22 EST 2012. Contains 205706 sequences.