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 A025724 #7 Jul 06 2025 14:10:26 %S A025724 1,3,6,10,15,21,28,36,45,55,66,78,92,107,123,140,158,177,197,218,240, %T A025724 263,287,312,339,367,396,426,457,489,522,556,591,627,664,703,743,784, %U A025724 826,869,913,958,1004,1051,1099,1148,1198,1250,1303,1357,1412,1468,1525,1583 %N A025724 Index of 7^n within sequence of numbers of form 6^i*7^j. %C A025724 Positions of zeros in A025660. - _R. J. Mathar_, Jul 06 2025 %K A025724 nonn %O A025724 1,2 %A A025724 _David W. Wilson_