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 A053789 #12 Jan 29 2018 21:13:02 %S A053789 2,2,2,7,2,3,2,2,2,3,2,3,2,3,2,7,2,3,2,3,2,3,2,3,2,3,2,3,2,3,2,41,2,3, %T A053789 2,3,2,3,2,3,2,59,2,7,2,3,2,3,2,7,2,37,2,2,5,2,2,89,2,3,2,3,2,7,2,3,2, %U A053789 3,2,3,2,3,2,3,2,3,2,3,2,3,2,3,2,13,2,109,2,2,17,2,2,2,7,2,7,2,2,7,2 %N A053789 a(n) = A020639(A053790(n)). %H A053789 Robert Israel, <a href="/A053789/b053789.txt">Table of n, a(n) for n = 1..10000</a> %e A053789 a(4) = 7 because the sum of the first 8 primes is 77 and 7 is its least prime divisor. %p A053789 N:= 2000: # to use primes <= N %p A053789 P:= select(isprime, [2, seq(i, i=3..N, 2)]): %p A053789 A053790:= remove(isprime, ListTools:-PartialSums(P)): %p A053789 map(t -> min(numtheory:-factorset(t)), A053790); # _Robert Israel_, Jan 29 2018 %Y A053789 Cf. A013918, A053790, A020639. %K A053789 easy,nonn %O A053789 1,1 %A A053789 _Enoch Haga_, Mar 27 2000 %E A053789 Edited by _N. J. A. Sloane_, Mar 16 2008, following explication by _R. J. Mathar_, Feb 26 2008