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.

A081382 a(1) = 1, for n > 1 a(n) = Min{x > n, A008472(x) = A008472(n)}.

Original entry on oeis.org

1, 4, 9, 8, 6, 12, 10, 16, 27, 20, 121, 18, 22, 28, 45, 32, 210, 24, 34, 40, 30, 44, 273, 25, 36, 52, 81, 56, 399, 60, 58, 64, 70, 68, 42, 48, 435, 76, 55, 49, 651, 84, 82, 88, 75, 92, 777, 54, 50, 80, 91, 104, 903, 72, 66, 98, 85, 116, 1645, 63, 118, 124, 90, 128, 77, 117
Offset: 1

Views

Author

Labos Elemer, Mar 26 2003

Keywords

Comments

Differs from A065642, a(n) <= A065642(n).

Crossrefs

Programs

  • Haskell
    a081382 1 = 1
    a081382 n = head [x | let sopf = a008472 n, x <- [n+1..], a008472 x == sopf]
    -- Reinhard Zumkeller, Jun 12 2015
  • Mathematica
    ffi[x_] := Flatten[FactorInteger[x]] lf[x_] := Length[FactorInteger[x]] ba[x_] := Table[Part[ffi[x], 2*w-1], {w, 1, lf[x]}] spf[x_] := Apply[Plus, ba[x]] Table[Min[Flatten[Position[Table[spf[w], {w, n+1, n^2}]-spf[n], 0]]+n], {n, 1, 100}]