A298419 a(n) = n*a(n-1) - a(n-2) + a([n/2]), where a(0) = 1, a(1) = 1, a(2) = 1.

1, 1, 1, 3, 12, 58, 339, 2318, 18217, 161647, 1598311, 17419832, 207440012, 2679300663, 37302771588, 556862275475, 8872493654229, 150275529864635, 2696087044070848, 51075378307643124, 1018811479110389943, 21343965683012143990, 468548433547174197669

Offset: 0

Author

Clark Kimberling, Feb 11 2018

Keywords

• nonn
• easy

Links

• Clark Kimberling, Table of n, a(n) for n = 0..1000

Crossrefs

Cf. A298338.

Programs

Mathematica

a[0] = 1; a[1] = 1; a[2] = 1;
a[n_] := a[n] = n a[n - 1] - a[n - 2] + a[Floor[n/2]];
Table[a[n], {n, 0, 30}]  (* A298419 *)