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 A060201 #24 Jun 22 2018 02:48:48 %S A060201 1,127,817,7651,13267,83167,188251,520417,751501,1332667,1689751, %T A060201 2519917,4691251,8331667,75015001,88015417,117206251,133326667, %U A060201 325510417,833316667,7500150001,9492356251,10950460417 %N A060201 Images of centered hexamorphic numbers: suppose k-th centered hexagonal number H_c(k) (A003215) ends in k; sequence gives value of H_c(k). %C A060201 Note that all centered hexamorphic numbers end in the digits 1 and 7. %D A060201 C. Pickover, Wonders of Numbers, Oxford University Press, NY, 2001, p. 152-155. %H A060201 C. A. Pickover, "Wonders of Numbers, Adventures in Mathematics, Mind and Meaning," <a href="http://www.zentralblatt-math.org/zmath/en/search/?q=an:0983.00008&format=complete">Zentralblatt review</a> %e A060201 127 is centered hexamorphic because it is the 7th centered hexagonal number and ends in 7. 817 is the 17th centered hexagonal and ends in 17. %o A060201 (PARI) lista(nn) = {for (n=0, nn, my(m = 3*n*(n-1)+1); if ((m - n) % 10^#Str(n) == 0, print1(m, ", ")););} \\ _Michel Marcus_, Jun 21 2018 %Y A060201 Cf. A003215. %K A060201 base,nonn %O A060201 1,2 %A A060201 _Jason Earls_, Mar 18 2001