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 A178303 #12 Sep 26 2018 03:30:29 %S A178303 13,182,312,2314,14235,125346,1234675,12348765,123456879,1023457968 %N A178303 Smallest multiple of 13 such that decimals digits 1, ..., k (k = 1, ..., 9) and 0 appear in any order. %C A178303 Divisibility of a number N by 13: add the digits of N in alternate blocks of three from right to left, then subtract the two sums: %C A178303 9th term: 123 456 879: (123 + 879) - 456 = 546, 546: 54 + (6 * 4) = 78 = 6 * 13. %D A178303 Faith Javane, Zahlenmystik: Das Handbuch der Numerologie, Goldmann - Arkana, Frankfurt, 1995 %D A178303 Helmut Kracke, Mathe - musische Knobelisken. Tüfteleien für Tüftler und Laien, Dümmler, Bonn, 1982 %D A178303 Hugo Steinhaus, Kaleidoskop der Mathematik, Deutscher Verlag der Wissenschaften, Berlin, 1959 %e A178303 1 * 13 = 13 %e A178303 14 * 13 = 182 %e A178303 24 * 13 = 312 %e A178303 178 * 13 = 2314 %e A178303 1095 * 13 = 14235 %e A178303 9642 * 13 = 125346 %e A178303 94975 * 13 = 1234675 %e A178303 949905 * 13 = 12348765 %e A178303 9496683 * 13 = 123456879 %e A178303 78727536 * 13 = 1023457968 %Y A178303 Cf. A171768, A171744. %K A178303 base,fini,full,nonn %O A178303 1,1 %A A178303 Eva-Maria Zschorn (e-m.zschorn(AT)zaschendorf.km3.de), May 24 2010, May 26 2010