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.

A261490 The total element sum of the n-fold f transform applied to the length n sequence of 1's. And f returns a sorted result after multiplying the elements in its input sequence with 1, 2, 3,... in descending size order.

Original entry on oeis.org

0, 1, 4, 19, 100, 633, 4626, 37878, 348224, 3542952, 39339852, 478962252, 6289532928, 89038853856, 1346224983936, 21729308136720, 371924399416320, 6740200653419520, 128878557725067264, 2598800542616444724, 54986036469506668800, 1217069235297874269792
Offset: 0

Views

Author

Alois P. Heinz, Aug 21 2015

Keywords

Crossrefs

Main diagonal of A166278.
Cf. A031971 (for ascending sort), A036740 (when sum is replaced by product).

Programs

  • Maple
    f:= l-> sort([seq(sort(l, `>`)[i]*i, i=1..nops(l))]):
    a:= n-> add(i, i=(f@@n)([1$n])):
    seq(a(n), n=0..35);