A081538 a(n) = A081537(n)/A081535(n), with a(2) = 1 by convention.

1, 1, 1, 2, 4, 1, 15, 33, 56, 495, 420, 330, 3960, 3432, 3003, 2574, 80080, 1601145, 1225224, 1108536, 1007760, 912912, 19399380, 17612595, 82372752, 149978400, 212469400, 196846650, 5354228880, 4976687100, 145568097675, 273491577450, 257403837600, 242695046880

Offset

1,4

Links

Table of n, a(n) for n=1..34.

Crossrefs

Cf. A081535, A081536, A081537.

Sequence in context: A184176 A163546 A172385 * A224783 A214058 A173820

Adjacent sequences: A081535 A081536 A081537 * A081539 A081540 A081541

Keyword

nonn

Author

Amarnath Murthy, Mar 28 2003

Extensions

Corrected, terms a(4)-a(19) added by Charlie Neder, Feb 03 2019

More terms from Jinyuan Wang, May 03 2020

Status

approved