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 A259991 #14 Jul 18 2015 16:59:23 %S A259991 8,148,344,36016,151264,1764736,46941952,1101076992,15858967552, %T A259991 139825248256,2453862488064,14602557997056,127990382747648, %U A259991 921705156001792,56481739283791872,523186025957228544,15768859390622826496,198716939766610001920,3186868919241067200512 %N A259991 This sequence and A259990 are base-14 analogs of A007185 and A016090, written in base 10. %C A259991 See Schut (1991) for precise definition. %C A259991 Ignoring repetitions, the subsequence of A201919 of terms ending in 8 in base 14. - _Eric M. Schmidt_, Jul 18 2015 %D A259991 C. P. Schut, Idempotents. Report AM-R9101, Centrum voor Wiskunde en Informatica, Amsterdam, 1991. %H A259991 Eric M. Schmidt, <a href="/A259991/b259991.txt">Table of n, a(n) for n = 1..500</a> %o A259991 (Sage) def a(n) : return crt(0, 1, 2^n, 7^n) # _Eric M. Schmidt_, Jul 18 2015 %Y A259991 Cf. A007185, A016090, A201919, A259986-A259991. %K A259991 nonn,base %O A259991 1,1 %A A259991 _N. J. A. Sloane_, Jul 13 2015 %E A259991 More terms from _Eric M. Schmidt_, Jul 18 2015