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A073014 (n!/2)*sum(k=1,n,(n+k)!/(k!)^3). 0
1, 9, 127, 2835, 93901, 4336878, 266268402, 20961918435, 2057633544961, 246291719185578, 35300219800649134, 5967365133741366446, 1174674087014062487490, 266337973265724541242428 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

a(n) is odd for n = 1,2,3 and if n is of the form 2^m or 2^m+1 (with m>= 2) (i.e. a(n) is odd if n=1,3,4,5,8,9,16,17,32,33,64,65,128,129,256,257...)

LINKS

Table of n, a(n) for n=1..14.

PROG

(PARI) a(n)=if(n<0, 0, (n!/2)*sum(k=1, n, (n+k)!/(k!)^3))

CROSSREFS

Sequence in context: A034301 A092651 A258294 * A046754 A203425 A275259

Adjacent sequences:  A073011 A073012 A073013 * A073015 A073016 A073017

KEYWORD

easy,nonn

AUTHOR

Benoit Cloitre, Aug 03 2002

STATUS

approved

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Last modified October 15 16:06 EDT 2021. Contains 348033 sequences. (Running on oeis4.)