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 A123213 #15 Nov 21 2024 12:33:30
%S A123213 21,93,1256,240111,16105118,482680929,41033867342,1698356304159,
%T A123213 180115266146378,420707233300201101,25408476896404831130,
%U A123213 6582952005840035281161,925103102315013629321198,73885357344138503765449239,12063348350820368238715343282
%N A123213 a(n) = A062457(n) concatenated with A014284(n).
%H A123213 Sergio Silva, <a href="https://web.archive.org/web/20061105083600/http://ginasiomental.no.sapo.pt/materialc/mteste/teste.htm">Teste Numerico</a>.
%e A123213 a(1) = 21 = 2 concatenated with 1.
%e A123213 a(2) = 93 = 9 concatenated with 3.
%e A123213 a(3) = 1256 = 125 concatenated with 6.
%e A123213 a(4) = 240111 = 2401 concatenated with 11.
%t A123213 rng=13;A062457=Table[Prime[n]^n, {n, rng}] ;A014284=Accumulate[Join[{1}, Prime[Range[rng-1]]]];Table[FromDigits[Join[IntegerDigits[A062457[[n]]],IntegerDigits[A014284[[n]]]]],{n,rng}] (* _James C. McMahon_, Nov 17 2024 *)
%o A123213 (PARI) s=1;print1(21,",");for(n=2,20,s=s+prime(n-1);print1(prime(n)^n,s,","))
%Y A123213 Cf. A014284, A062457.
%K A123213 base,nonn,less
%O A123213 1,1
%A A123213 Herman Jamke (hermanjamke(AT)fastmail.fm), Oct 05 2006