A237717 Numerators corresponding to A237425(n).

2, 1, 1, -1, -1, 1, 1, -17, -1, 31, 5, -691, -691, 5461, 7, -929569, -3617, 3202291, 43867, -221930581, -174611, 4722116521, 854513, -968383680827, -236364091, 14717667114151, 8553103, -2093660879252671, -23749461029, 86125672563201181

Offset: 0

Author

Jean-François Alcover and Paul Curtz, Feb 24 2014

Keywords

• sign
• frac

Comments

This autosequence (a sequence which has its inverse binomial transform equal to the signed sequence) is related to Bernoulli and Euler numbers. For more details, see A237425.

Links

• Vincenzo Librandi, Table of n, a(n) for n = 0..200

Crossrefs

Cf. A000367, A089171, A237425.

Programs

Mathematica

b[0] = 2; b[1] = 1; b[n_] := BernoulliB[n] + EulerE[n, 1]/2^IntegerExponent[n, 2]; a[n_] := Numerator[b[n]]; Table[a[n], {n, 0, 55}]

Formula

a(2n+2) = A000367(n+1), a(2n+1) = A089171(n).