A249945 a(n) = n! + 3^n.

2, 4, 11, 33, 105, 363, 1449, 7227, 46881, 382563, 3687849, 40093947, 479533041, 6228615123, 87183074169, 1307688716907, 20922832934721, 355687557236163, 6402374093148489, 121645101571093467, 2432902011663424401, 51090942182169793203, 1124000727808988739609

Offset: 0

Author

Max Alweiss, Nov 08 2014

Keywords

• nonn
• easy

Crossrefs

Cf. A000142, A000244, A007611.

Programs

Magma

[3^n+Factorial(n) : n in [0..25]]; // Wesley Ivan Hurt, Nov 14 2014

Maple

A249945:=n->3^n+n!: seq(A249945(n), n=0..25); # Wesley Ivan Hurt, Nov 14 2014

Mathematica

Table[3^n + n!, {n, 20}] (* Alonso del Arte, Nov 09 2014 *)

PARI

vector(10,n,3^n + n!) \\ Derek Orr, Nov 14 2014

Formula

a(n) = n! + 3^n.

a(n) = A000142(n) + A000244(n).

E.g.f.: 1/(1-x) + exp(3*x). - Alois P. Heinz, Aug 29 2022