A176727 Denominator of a-sequence for Sheffer triangle A060081.

1, 1, 3, 1, 15, 1, 21, 1, 45, 1, 33, 1, 1365, 1, 45, 1, 765, 1, 399, 1, 3465, 1, 1035, 1, 20475, 1, 189, 1, 435, 1, 7161, 1, 58905, 1, 315, 1, 959595, 1, 117, 1, 20295, 1, 148995, 1, 108675, 1, 14805, 1, 2436525, 1, 65637, 1, 78705, 1, 21945, 1, 24795, 1, 531, 1, 85180095, 1, 135135

Offset: 0

Author

Wolfdieter Lang, Jul 14 2010

Keywords

• nonn
• easy
• frac

Comments

The numerator sequence is A176726.

For a- and z-sequences for Sheffer triangles see the W. Lang link under A006232.

Examples

			Rationals A176726(n)/A176727(n): [1, 0, -2/3, 0, -32/15, 0, -704/21,0,...].
		

Links

• W. Lang: Rationals A176726/A176727.

Crossrefs

A176728/A176729 z-sequence for triangle A060081.

Programs

Mathematica

max = 63; s = x/Log[Sqrt[(1+x)/(1-x)]] + O[x]^max; CoefficientList[s, x] * Range[0, max-1]! // Denominator (* Jean-François Alcover, Oct 04 2016 *)

Formula

E.g.f. for rational a-sequence A176726/A176727: x/log(sqrt((1+x)/(1- x))).