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.

Showing 1-1 of 1 results.

A339057 a(n) = (-1)^(n + 1)*3^(2*n + 1)*Euler(2*n + 1, 1/3)*2^(valuation_{2}(2*(n + 1))), the Steinhaus-Euler sequence S_{3}(n).

Original entry on oeis.org

1, 13, 121, 18581, 305071, 61203943, 4353296221, 6669149100757, 206772189255571, 128970681211645873, 24697503335329725121, 45583359018138184284551, 6235055851689626935206871, 7982707567621372702411448803, 2955418704408380517540605162821, 40101878131071637461151318174173269
Offset: 0

Views

Author

Peter Luschny, Nov 27 2020

Keywords

Examples

			The array of the general case S_{k}(n) starts:
[k]
[1] -1, -1,   -1,     -17,      -31,        -691,         -5461, ... [-A002425]
[2]  0,  0,    0,       0,        0,           0,             0, ...
[3]  1, 13,  121,   18581,   305071,    61203943,    4353296221, ... [this seq.]
[4]  2, 44,  722,  196888,  5746082,  2049374444,  259141449842, ...
[5]  3, 99, 2523, 1074243, 48982293, 27296351769, 5393115879063, ...
...
		

Crossrefs

Programs

  • Maple
    GenEuler := k -> (n -> (-1)^n*(-k)^(2*n+1)*euler(2*n+1, 1/k)):
    Steinhaus := n -> 2^padic[ordp](2*(n+1), 2):
    seq(Steinhaus(n)*GenEuler(3)(n), n = 0..15);
  • Mathematica
    GenEuler[n_, k_] := (-1)^n (-k)^(2 n + 1) EulerE[2 n + 1, 1/k] ;
    Steinhaus[n_] := 2^IntegerExponent[2*(n+1), 2];
    a[n_] := GenEuler[n, 3] Steinhaus[n]; Table[a[n], {n, 0, 15}]
Showing 1-1 of 1 results.