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 A245415 #10 Jul 22 2014 12:35:12 %S A245415 5,10,25,60,150,375,940,2350,5875,14685,36715,91785,229465,573660, %T A245415 1434150,3585375,8963440,22408600,56021500,140053750,350134375, %U A245415 875335935,2188339840,5470849600,13677124000,34192810000,85482025000,213705062500,534262656250 %N A245415 Number of nonnegative integers with property that their base 5/2 expansion (see A024632) has n digits. %e A245415 a(2) = 10 because 20, 21, 22, 23, 24, 40, 41, 42, 43 and 44 are the base 5/2 expansions for the integers 5, 6, 7, 8, 9, 10, 11, 12, 13 and 14 respectively and these are the only integers with 2 digits. %o A245415 (Sage) %o A245415 A=[1] %o A245415 for i in [1..60]: %o A245415 A.append(ceil(((5-2)/2)*sum(A))) %o A245415 [5*x for x in A] %Y A245415 Cf. A081848, A245356, A024632. %K A245415 nonn,base %O A245415 1,1 %A A245415 _Hailey R. Olafson_, Jul 21 2014