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 A025731 #10 Jul 06 2025 14:17:10 %S A025731 1,3,6,10,15,21,28,36,45,55,66,78,91,105,120,137,155,174,194,215,237, %T A025731 260,284,309,335,362,390,419,449,480,513,547,582,618,655,693,732,772, %U A025731 813,855,898,942,987,1033,1081,1130,1180,1231,1283,1336,1390,1445,1501,1558,1616 %N A025731 Index of 8^n within sequence of numbers of form 7^i*8^j. %C A025731 Positions of zeros in A025669. - _R. J. Mathar_, Jul 06 2025 %Y A025731 Cf. A001018, A036566. %K A025731 nonn %O A025731 1,2 %A A025731 _David W. Wilson_