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.

A168562 Sum of squares of Eulerian numbers in row n of triangle A008292 with a(0)=1.

Original entry on oeis.org

1, 1, 2, 18, 244, 5710, 188908, 8702820, 524888040, 40393084950, 3853034107900, 446671026849916, 61824801560228056, 10072685383683311116, 1907978676359896992824, 415795605119514578204616, 103294156408291202467520976, 29018125910193347265466916070
Offset: 0

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Author

Paul D. Hanna, Nov 29 2009

Keywords

Comments

Row sums of Eulerian triangle A008292 yield the factorials.

Examples

			a(1) = 1 = 1;
a(2) = 1 + 1 = 2;
a(3) = 1 + 4^2 + 1 = 18;
a(4) = 1 + 11^2 + 11^2 + 1 = 244;
a(5) = 1 + 26^2 + 66^2 + 26^2 + 1 = 5710;
a(6) = 1 + 57^2 + 302^2 + 302^2 + 57^2 + 1 = 188908.
		

Crossrefs

Cf. A008292.
Column k=2 of A335545.

Programs

  • Maple
    a:= n-> add(combinat[eulerian1](n, k)^2, k=0..n):
    seq(a(n), n=0..18);  # Alois P. Heinz, Sep 10 2020
  • PARI
    {a(n)=sum(k=0,n,sum(j=0, k, (-1)^j*(k-j)^n*binomial(n+1, j))^2)}

Formula

a(n) = Sum_{k=0..n} [ Sum_{j=0..k} (-1)^j*(k-j)^n*C(n+1, j) ]^2.