cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A292791 The numerator of the real part of E(2n-1, i), where E(n, x) is the Euler polynomial.

Original entry on oeis.org

-1, 7, -11, 199, -361, 8017, -63311, 10775663, -37120861, 2572609327, -54738555011, 11225458402189, -170606509547761, 24269619087650437, -998364772178081111, 1505193846304099711711, -10065529459831250937061, 2427246234079407797537347, -163790353311268893725697611
Offset: 1

Views

Author

Robert G. Wilson v, Sep 23 2017

Keywords

Comments

The imaginary part is +-i.
The denominators are powers of two; A171977(n) = 2^A001511(n).
For E(2n, i) see A292792.
a(4n) == +-1 (mod 6),
a(4n+1) == 5 (mod 6),
a(4n+2) == 1 (mod 6),
a(4n+3) == 1 (mod 6).
Inspired by A291897.

Examples

			a(3) = -11 since E(5, i) = -11/2 + i.
		

Crossrefs

Cf. A292792.

Programs

  • Mathematica
    f[n_] := Numerator[ EulerE[2n -1, I] - I^(2n -1)]; Array[f, 19]