A178684 - OEIS

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A178684

Partial sums of cardinalities of coalition sets A095941.

0, 0, 1, 5, 18, 53, 138, 332, 757, 1661, 3546, 7424, 15328, 31336, 63618, 128531, 258811, 519956, 1042992, 2090009, 4185231, 8377158, 16762853, 33536516, 67086633, 134190278, 268401718, 536829625, 1073691505, 2147422558

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OFFSET

1,4

COMMENTS

Partial sums of number of subsets of {1,2,...,n} such that every number in the set is no larger than the sum of the other numbers in the set. See formula in A095944. The subsequence of primes begins: 5, 53, 757, 2090009, 16762853.

LINKS

Table of n, a(n) for n=1..30.

EXAMPLE

a(9) = 0 + 0 + 1 + 4 + 13 + 35 + 85 + 194 + 425 = 757 is prime.

CROSSREFS

Cf. A000009, A002623, A095941, A095944.

Sequence in context: A127983 A226903 A056782 * A353689 A271771 A270990

Adjacent sequences: A178681 A178682 A178683 * A178685 A178686 A178687

KEYWORD

nonn,easy

AUTHOR

Jonathan Vos Post, Dec 25 2010

STATUS

approved