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 A039790 #29 Apr 05 2021 20:41:19 %S A039790 12,13,15,17,111,113,117,119,123,129,131,137,141,143,147,153,159,161, %T A039790 167,171,173,179,183,189,197,1101,1103,1107,1109,1113,1127,1131,1137, %U A039790 1139,1149,1151,1157,1163,1167,1173,1179,1181,1191,1193,1197,1199,1211 %N A039790 Prime numbers prefixed with a '1'. %C A039790 Replace every prime by the concatenation of its divisors. [_Lekraj Beedassy_, May 29 2009] %H A039790 David F. Marrs, <a href="/A039790/b039790.txt">Table of n, a(n) for n = 1..10000</a> %H A039790 Kevin N. Stone, <a href="https://web.archive.org/web/20190613194636/https://www.brainbashers.com/showpuzzles.asp?puzzle=ZBLZ">What number comes next in this sequence</a>, BrainBashers [Archived copy at the Wayback Machine]. %F A039790 a(n) = A037278(A000040(n)). [_Lekraj Beedassy_, May 29 2009] %t A039790 Array[10^Floor[1 + Log10[#]] + # &@ Prime[#] &, 47] (* _Michael De Vlieger_, Apr 05 2021 *) %o A039790 (PARI) a(n) = eval(concat(Str(1), Str(prime(n)))) \\ _Felix Fröhlich_, Apr 05 2021 %Y A039790 Cf. A000040, A037278, A289866 (terms which are prime). %K A039790 nonn,base,dumb %O A039790 1,1 %A A039790 Kevin N. Stone (kevin.stone(AT)brainbashers.com)