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 A134821 #4 Mar 30 2012 17:33:50 %S A134821 1,12,4921,51127323835,218857981551141835113634, %T A134821 310572853467235677965363821819928450852019, %U A134821 1425475594007632231129760415319272779790434025012566981847673007772802 %N A134821 Concatenation of next n Motzkin numbers. %Y A134821 Cf. A053067, A053068, A133013. Motzkin numbers: A001006. %K A134821 easy,nonn,base %O A134821 1,2 %A A134821 _Omar E. Pol_, Nov 12 2007 %E A134821 Edited by _Charles R Greathouse IV_, Apr 25 2010