A130188 Denominators of rationals r(n) related to the z-sequence of the Sheffer matrix A060821 for Hermite polynomials.

1, 4, 4, 32, 16, 64, 64, 1024, 256, 1024, 1024, 8192, 4096, 16384, 16384, 524288, 65536, 262144, 262144, 2097152, 1048576, 4194304, 4194304, 67108864, 16777216, 67108864, 67108864, 536870912, 268435456, 1073741824

Offset: 0

Author

Wolfdieter Lang Jun 01 2007

Keywords

• nonn
• frac
• easy

Comments

Numerators are A130187.

See A130187 for details on r(n):= A130187(n)/a(n) and the corresponding z-sequence for the Hermite matrix A060821.

Links

• G. C. Greubel, Table of n, a(n) for n = 0..1000

Programs

Mathematica

F:= CoefficientList[Series[-2*(Exp[x^2/4] -1)/x, {x,0,75}], x]*Range[0, 75]!; Table[Denominator[-2*F[[2*n]]], {n, 1, 50}] (* G. C. Greubel, Jul 10 2018 *)

Formula

a(n) = denominator(-2*z(2*n+1)), n>=0, with the e.g.f. for z(n) given in A130187.