A316333 a(n) = A000085(4*n+3)/2^(n+2).

1, 29, 2231, 323423, 75151585, 25451905333, 11799518538967, 7161375112402823, 5503252915369107329, 5217568316626716585485, 5977663757214838174587319, 8136442760259565566724537711, 12972630954295515566319694027489, 23938932303527622015634131021262757

Offset: 0

Author

N. J. A. Sloane, Jul 09 2018, following a suggestion from Doron Zeilberger

Keywords

• nonn

Links

• Seiichi Manyama, Table of n, a(n) for n = 0..210
• S. Chowla, I. N. Herstein and W. K. Moore, On recursions connected with symmetric groups I, Canad. J. Math. 3 (1951) 328-334.
• Dongsu Kim and Jang Soo Kim, A combinatorial approach to the power of 2 in the number of involutions, J. Comb. Theory Ser. A 117 (8) (2010): 1082-1094.

Crossrefs

Cf. A000085, A316330, A316331, A316332.