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.

A360321 a(n) = Sum_{k=0..n} 5^(n-k) * binomial(n-1,n-k) * binomial(2*k,k).

Table of values

n a(n)
0 1
1 2
2 16
3 130
4 1070
5 8902
6 74724
7 631902
8 5376840
9 45990070
10 395106656
11 3407196982
12 29477061166
13 255733684010
14 2224098916300
15 19384492018770
16 169270624419390
17 1480625235653670
18 12970844831940000
19 113785067475668550
20 999400688480388570

List of values

[1, 2, 16, 130, 1070, 8902, 74724, 631902, 5376840, 45990070, 395106656, 3407196982, 29477061166, 255733684010, 2224098916300, 19384492018770, 169270624419390, 1480625235653670, 12970844831940000, 113785067475668550, 999400688480388570]

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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