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A138525 a(n) = Sum_{k=0..n} (2*k)!. 5
1, 3, 27, 747, 41067, 3669867, 482671467, 87660962667, 21010450850667, 6423384156578667, 2439325392333218667, 1126440053169940898667, 621574841786409380258667, 403913035968392044964258667 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,2
COMMENTS
Last digit is 7 for n > 2. Therefore there is no square in this sequence except 1. - Altug Alkan, Dec 01 2015
LINKS
MAPLE
A138525:=n->add((2*k)!, k=0..n): seq(A138525(n), n=0..15); # Wesley Ivan Hurt, Dec 01 2015
MATHEMATICA
Table[Sum[(2i)!, {i, 0, n}], {n, 0, 15}] (* Stefan Steinerberger, Mar 25 2008 *)
PROG
(PARI) a(n) = sum(k=0, n, (2*k)!); \\ Altug Alkan, Dec 01 2015
CROSSREFS
Partial sums of A010050.
Sequence in context: A047656 A193610 A052269 * A185149 A326086 A194500
KEYWORD
easy,nonn
AUTHOR
Leroy Quet, Mar 23 2008
EXTENSIONS
More terms from Stefan Steinerberger and Robert G. Wilson v, Mar 25 2008
STATUS
approved

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Last modified March 28 09:04 EDT 2024. Contains 371240 sequences. (Running on oeis4.)