A098698 Main diagonal of array in A098697.

1, 4, 64, 1778, 73848, 4188592, 306690520, 27893327856, 3063657097664, 397720778283584, 59997757426314624, 10373545999796847232, 2032368096229682220160, 446879795164524710777856

Offset: 0

Author

Ralf Stephan, Sep 23 2004

Keywords

• nonn

Comments

Diagonal of Euler-Seidel matrix with start sequence A000248.

Programs

Mathematica

a248[0] = 1; a248[n_] := Sum[Binomial[n, k]*(n - k)^k, {k, 0, n}];
T[0, n_] := T[0, n] = a248[n]; T[k_, n_] := T[k, n] = T[k - 1, n] + T[k - 1, n + 1];
a[n_] := T[n, n];
Table[a[n], {n, 0, 13}] (* Jean-François Alcover, Nov 08 2017 *)

Formula

a(n) = Sum_{k=0..n} C(n, k) * A000248(2n-k).