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 A025722 #7 Jul 06 2025 14:09:17 %S A025722 1,3,6,11,17,25,34,44,56,69,84,100,117,136,156,178,201,225,251,278, %T A025722 307,337,368,401,435,471,508,546,586,627,670,714,759,806,854,904,955, %U A025722 1007,1061,1116,1173,1231,1290,1351,1413,1477,1542,1608,1676,1745,1816,1888 %N A025722 Index of 7^n within sequence of numbers of form 4^i*7^j. %C A025722 Positions of zeros in A025648. - _R. J. Mathar_, Jul 06 2025 %K A025722 nonn %O A025722 1,2 %A A025722 _David W. Wilson_