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A070781 a(n) = binomial((n+1)^2, n^2). 1
1, 4, 126, 11440, 2042975, 600805296, 262596783764, 159518999862720, 128447994798305325, 132341572939212267400, 169758547725351091518726, 265242021590899282966358400, 495874093230232452749553398586, 1092844289151775603486607296657120 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

All primes between n^2 and (n+1)^2 divide a(n). No prime between (n+1)^2/2 and n^2 divides a(n). Every prime greater than n+1 has exponent 0 or 1 in the prime factorization of a(n). - T. D. Noe, Aug 09 2008

LINKS

T. D. Noe, Table of n, a(n) for n=0..50

MATHEMATICA

Binomial[#[[2]], #[[1]]]&/@Partition[Range[0, 20]^2, 2, 1] (* Harvey P. Dale, Jul 29 2015 *)

CROSSREFS

Sequence in context: A253099 A178842 A054053 * A152421 A270959 A291851

Adjacent sequences:  A070778 A070779 A070780 * A070782 A070783 A070784

KEYWORD

nonn

AUTHOR

Karol A. Penson, May 06 2002

EXTENSIONS

Better definition from Amarnath Murthy, Jul 14 2005

One more term (a(13)) added by Harvey P. Dale, Jul 29 2015

STATUS

approved

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Last modified June 23 17:11 EDT 2021. Contains 345402 sequences. (Running on oeis4.)