A082292 - OEIS

A082292

a(n) = (2n+1) * (2n)! / sqrt(4*(n+1)*Product_{k=1..2n+1} lcm(k, 2n+2-k)).

1, 1, 2, 12, 4, 8, 72, 160, 16, 3456, 32, 1792, 129600, 1024, 128, 1492992, 256, 2048000, 18289152, 180224, 1024, 573308928, 1280000, 1703936, 241864704, 719323136, 8192, 64497254400000, 16384, 33554432, 234125033472, 142606336

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OFFSET

2,3

LINKS

Table of n, a(n) for n=2..33.

MATHEMATICA

Table[((2n+1)(2n)!)/Sqrt[4(n+1)Product[LCM[k, 2n+2-k], {k, 2n+1}]], {n, 2, 40}] (* Harvey P. Dale, Aug 01 2020 *)

PROG

(PARI) for(i=2, 20, n=i*2+1; p=1; for(k=1, n, p=p*lcm(k, n+1-k)); print1((2*i+1)*(2*i)!/sqrtint(4*(i+1)*p)", "))

CROSSREFS

Cf. A082022.

Sequence in context: A164869 A347408 A248030 * A248588 A332350 A164857

Adjacent sequences: A082289 A082290 A082291 * A082293 A082294 A082295

KEYWORD

nonn

AUTHOR

Ralf Stephan, Apr 08 2003

STATUS

approved