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 A302188 #14 Nov 28 2024 07:38:24 %S A302188 1,3,12,53,252,1252,6416,33609,178996,965660,5263728,28936404, %T A302188 160204336,892313424,4995832640,28096475977,158638993476,898844200524, %U A302188 5108695394096,29117034808980,166370716319088,952789631705104,5467881256289856,31438798094242244,181079794531199440,1044651995141484912 %N A302188 Number of 3D walks of type bce. %C A302188 See Dershowitz (2017) for precise definition. %C A302188 Binomial transform of A150500 (Number of 3D walks of type bcd). - _Mélika Tebni_, Nov 28 2024 %H A302188 Nachum Dershowitz, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL20/Dershowitz/dersh3.html">Touchard's Drunkard</a>, Journal of Integer Sequences, Vol. 20 (2017), #17.1.5. %o A302188 (Python) %o A302188 from math import comb as binomial %o A302188 def a(n): %o A302188 return sum(binomial(n, k)*sum(binomial(k, j)*binomial(j, j//2)**2 for j in range(k+1)) for k in range(n+1)) %o A302188 print([a(n) for n in range(26)]) # _Mélika Tebni_, Nov 28 2024 %Y A302188 Cf. A000108, A000984, A002212, A002896, A005572, A026375, A064037, A081671, A138547, A145847, A145867, A150500, A202814. %K A302188 nonn,walk %O A302188 0,2 %A A302188 _N. J. A. Sloane_, Apr 09 2018 %E A302188 a(12)-a(25) from _Mélika Tebni_, Nov 28 2024