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.

A007447 Logarithm of e.g.f. for primes.

Original entry on oeis.org

2, -1, 3, -12, 59, -354, 2535, -21190, 202731, -2183462, 26130441, -343956264, 4938891841, -76827253854, 1287026203647, -23100628140676, 442271719973507, -8996704216880580, 193776558133638811, -4405549734148088108, 105432710994387193283, -2649353692976978990070
Offset: 1

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Author

Keywords

References

  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Crossrefs

Programs

  • Maple
    a:= proc(n) option remember; (t-> `if`(n=0, 0, t(n) -add(j*
          binomial(n, j)*t(n-j)*a(j), j=1..n-1)/n))(i->ithprime(i))
        end:
    seq(a(n), n=1..25);  # Alois P. Heinz, Mar 06 2018
  • Mathematica
    a[n_] := a[n] = Function[t, If[n==0, 0, t[n] - Sum[j Binomial[n, j] t[n-j] a[j], {j, 1, n-1}]/n]][Prime];
    Array[a, 25] (* Jean-François Alcover, Oct 30 2020, after Alois P. Heinz *)

Formula

E.g.f.: log(1 + Sum_{k>=1} prime(k)*x^k/k!). - Ilya Gutkovskiy, Mar 10 2018

Extensions

Signs from Christian G. Bower, Nov 15 1998