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 A134180 #18 Jan 30 2021 13:07:02 %S A134180 1,3,5,7,9,13,23,25,29,55,117,119,123,173,187,193,205,213,223,249,255, %T A134180 259,265,285,299,311,329,351,393,397,411,483,487,513,515,525,563,587, %U A134180 597,607,637,645,647,679,709,789,871,877,911,953,971,985,1015,1051,1075 %N A134180 Indices of primes in A007468. %C A134180 Compute sums of k distinct sequential primes (no overlap). If the sums are prime add their indices to the sequence. %H A134180 Chai Wah Wu, <a href="/A134180/b134180.txt">Table of n, a(n) for n = 1..1000</a> %e A134180 a(2)=3 because this k value is the index for the next 3 primes in sequence to be summed. k=1 is 2, k=2 is 3+5 and k=3 is 7+11+13=31. The sums at k=1 and k=3 are prime, while k=2 is composite. %o A134180 (UBASIC) %o A134180 10 K=1 %o A134180 20 A=nxtprm(A): B=B+A: C=C+1: if C<>K then 20: else 30 %o A134180 30 L=B/K %o A134180 31 print K;B;: Q=prmdiv(B): if Q=B then print B; "-": stop: else 40 %o A134180 40 B=0: K=K+1: C=0: goto 20 %Y A134180 Cf. A007468. Corresponding primes are listed in A134179. %Y A134180 Cf. A134244, A134245, A134246. %K A134180 easy,nonn %O A134180 1,2 %A A134180 _Enoch Haga_, Oct 16 2007