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A072953 a(n)=sum(k=1,n,C(n,n reduced (mod k))). 0
1, 2, 5, 7, 22, 25, 79, 124, 276, 444, 1267, 1657, 4435, 7753, 17327, 28309, 72728, 110949, 279663, 476090, 1071672, 1834419, 4512625, 7194685, 17326148, 30229021, 68385742, 117709413, 280395840, 466385404, 1099376097, 1923155966 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..32.

FORMULA

Observation: lim n -> infinity a(n+2)/a(n) = 4 and it seems that a(n+2)/a(n) < 4 or >4 for infinitely many values of n.

MATHEMATICA

Table[Sum[Binomial[n, Mod[n, k]], {k, n}], {n, 40}] (* Harvey P. Dale, Jul 16 2017 *)

PROG

(PARI) a(n)=sum(k=1, n, binomial(n, n%k))

CROSSREFS

Sequence in context: A327322 A160820 A158357 * A243394 A175552 A279756

Adjacent sequences:  A072950 A072951 A072952 * A072954 A072955 A072956

KEYWORD

nonn

AUTHOR

Benoit Cloitre, Aug 20 2002

STATUS

approved

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Last modified June 6 01:51 EDT 2020. Contains 334858 sequences. (Running on oeis4.)