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.

A367850 Total sum of the block maxima minus the block minima over all partitions of [n].

Original entry on oeis.org

0, 0, 1, 6, 33, 182, 1034, 6122, 37927, 246030, 1669941, 11844324, 87644672, 675494180, 5413500801, 45040155758, 388441330457, 3467619369538, 31998729152474, 304846692965822, 2994781617653439, 30304301968015582, 315536869771786501, 3377398077726963112
Offset: 0

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Author

Alois P. Heinz, Dec 15 2023

Keywords

Examples

			a(3) = 6 = 2 + 1 + 2 + 1 + 0: 123, 12|3, 13|2, 1|23, 1|2|3.
		

Crossrefs

Cf. A000110, A002538 (the same for permutations), A002620, A120325, A124325, A278677, A368338.

Programs

  • Maple
    b:= proc(n, m, t) option remember; `if`(n=0, [1, 0], (p->
          p+[0, p[1]*(n-t)])(b(n-1, m+1, t+1))+m*b(n-1, m, t+1))
        end:
    a:= n-> b(n, 0, 1)[2]:
    seq(a(n), n=0..23);
    # second Maple program:
    egf:= (z-2)*exp(2*z+exp(z)-1)+(2*z+1)*exp(z+exp(z)-1)+exp(exp(z)-1):
    a:= n-> n!*coeff(series(egf, z, n+1), z, n):
    seq(a(n), n=0..23);

Formula

E.g.f.: (z-2)*exp(2*z+exp(z)-1)+(2*z+1)*exp(z+exp(z)-1)+exp(exp(z)-1).
a(n) = A278677(n-1) - A124325(n+1) for n>=1.
a(n) = Bell(n+1)+(n+1)*Bell(n)-Bell(n+2)+Sum_{k=0..n} Stirling2(n+1,k)*(n+1-k).
a(n) = Sum_{k=0..A002620(n)} k * A368338(n,k).
a(n) mod 2 = A120325(n).