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 A245430 #8 Jul 22 2014 22:19:10 %S A245430 9,9,18,36,63,108,198,360,648,1161,2088,3762,6768,12186,21933,39483, %T A245430 71064,127917,230256,414459,746028,1342845,2417121,4350816,7831476, %U A245430 14096655,25373979,45673164,82211688,147981042,266365872,479458575,863025435,1553445783,2796202404 %N A245430 Number of nonnegative integers with property that their base 9/5 expansion (see A024653) has n digits. %e A245430 The numbers 9-17 are represented by 50, 51, 52, 53, 54, 55, 56, 57, 58 respectively in base 9/5. Since these are the only two digit integers we have a(2) = 9. %o A245430 (Sage) %o A245430 A=[1] %o A245430 for i in [1..100]: %o A245430 A.append(ceil(((9-5)/5)*sum(A))) %o A245430 [9*x for x in A] %Y A245430 Cf. A024653, A245356, A081848. %K A245430 nonn,base %O A245430 1,1 %A A245430 _Tom Edgar_, Jul 21 2014