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 A064642 #15 Apr 18 2020 22:08:54 %S A064642 1,1,2,1,5,7,1,8,22,29,1,11,46,104,133,1,14,79,251,517,650,1,17,121, %T A064642 497,1369,2669,3319,1,20,172,869,2986,7541,14179,17498,1,23,232,1394, %U A064642 5746,17642,42031,77027,94525,1,26,301,2099,10108,36482,103696,236933 %N A064642 Triangle defined in A064641 read by rows. %C A064642 Or, Dziemianczuk's array P(i,j) read by antidiagonals: %C A064642 1 2 7 29 133 650 3319 17498 ... %C A064642 1 5 22 104 517 2669 14179 77027 ... %C A064642 1 8 46 251 1369 7541 42031 236933 ... %C A064642 1 11 79 497 2986 17642 103696 609428 ... %C A064642 1 14 121 869 5746 36482 226768 1393637 ... %C A064642 ... %H A064642 Peter Kagey, <a href="/A064642/b064642.txt">Table of n, a(n) for n = 0..10010</a> (first 141 rows, flattened) %H A064642 M. Dziemianczuk, <a href="http://dx.doi.org/10.1007/s00373-013-1357-1">Counting Lattice Paths With Four Types of Steps</a>, Graphs and Combinatorics, September 2013, Volume 30, Issue 6, pp 1427-1452. %e A064642 Triangle begins %e A064642 1; %e A064642 1, 2; %e A064642 1, 5, 7; %e A064642 1, 8, 22, 29; %e A064642 ... %Y A064642 Cf. A064641, A232972. %K A064642 nonn,tabl %O A064642 0,3 %A A064642 _Floor van Lamoen_, Oct 03 2001