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.
%I A239553 #6 Aug 28 2014 03:59:13
%S A239553 1,1,1,2,4,7,13,23,40,73,132,235,425,767,1379,2491,4495,8105,14629,
%T A239553 26407,47647,86009,155251,280202,505771,912930,1647796,2974292,
%U A239553 5368610,9690288,17491016,31571338,56986216,102860299,185663064,335122028,604896038,1091838582
%N A239553 Number of compositions of n such that the first part is 1 and the second differences of the parts are in {-3,...,3}.
%H A239553 Alois P. Heinz, <a href="/A239553/b239553.txt">Table of n, a(n) for n = 0..1000</a>
%F A239553 a(n) ~ c * d^n, where d = 1.80500192473773030222699209897983267121107478038035391729605116..., c = 0.35357751116733859348564640393076257358506245520421137739865819... . - _Vaclav Kotesovec_, Aug 28 2014
%Y A239553 Column k=3 of A239550.
%K A239553 nonn
%O A239553 0,4
%A A239553 _Alois P. Heinz_, Mar 21 2014