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.

A307903 Coefficient of x^n in (1 + n*x + n*x^3)^n.

Table of values

n a(n)
0 1
1 1
2 4
3 36
4 448
5 6875
6 124956
7 2624293
8 62537728
9 1667191653
10 49158400000
11 1588285928306
12 55796298391296
13 2117279603738494
14 86299754734693696
15 3760031421065559375
16 174374733095888748544
17 8575617145497637681301
18 445758339115421869936896
19 24417549315693295193935516

List of values

[1, 1, 4, 36, 448, 6875, 124956, 2624293, 62537728, 1667191653, 49158400000, 1588285928306, 55796298391296, 2117279603738494, 86299754734693696, 3760031421065559375, 174374733095888748544, 8575617145497637681301, 445758339115421869936896, 24417549315693295193935516]