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 A330309 #21 Dec 12 2019 17:49:48 %S A330309 11,751,1129,361649,361649,12462809,12462809,1273183931,1273183931, %T A330309 671946598957,1936133384597 %N A330309 Smallest prime p such that the sum of all powers of primes 2^2 + 3^3 + ... + p^p up to p is a multiple of 10^n. %C A330309 Suggested in a discussion in Mersenneforum, with contributions by users (among others) "davar55", _Benjamin R. Buhrow_, and _Charles R Greathouse IV_. The latter calculated the terms a(1)-a(9) of this sequence (see link). %H A330309 Charles R Greathouse IV and others, <a href="https://www.mersenneforum.org/showthread.php?t=13181&page=11">Sums of Squares</a>, thread in Mersenneforum, December 2010. %e A330309 a(1) = 11: 2^2 = 4, 2^2 + 3^3 = 31, 2^2 + 3^3 + 5^5 = 3156, 2^2 + 3^3 + 5^5 + 7^7 = 826699, 2^2 + 3^3 + 5^5 + 7^7 + 11^11 = 285312497310 -> smallest sum divisible by 10^1. %o A330309 (PARI) for(n=1,4,my(n10=10^n,s=0);forprime(p=2,oo,s+=p^p;if(!(s%n10),print1(p,", ");break))) %Y A330309 Cf. A174106, A174862, A330308. %K A330309 nonn,more,hard %O A330309 1,1 %A A330309 _Hugo Pfoertner_, Dec 10 2019 %E A330309 a(10)-a(11) from _Giovanni Resta_, Dec 11 2019