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 A132809 #7 Sep 17 2015 03:01:08
%S A132809 3,3,5,71,5,7,17,239,13,29,5,43,23,5,5,7,7,79,17,47,11,109,73,97,53,
%T A132809 271,13,263,23,41,61,97,101,181,41,47,13,233,13,53,13,359,151,71,61,
%U A132809 239,73,443,859,29,131,131,61,313,101,19,151,521,3,571,31,7,79,109,97,53,53
%N A132809 First prime in a sequence of n consecutive odd primes with integral arithmetic mean.
%C A132809 See A054892 for another version.
%F A132809 a(n) = {min (prime(k)): sum_{i=0..n-1} prime(k+i) = 0 mod n, k>1 }. - _R. J. Mathar_, Nov 27 2007
%e A132809 For n=2 we add prime(2)+prime(3)=3+5=8 which is already a multiple of n=2, so we add the first of the primes, 3, at a(n=2).
%e A132809 For n=5 we test 3+5+7+11+13=39 against being a multiple of n=5, then 5+7+11+13+17=53, then 7+11+13+17+19=67 etc. and find that 71+73+79+83+89=395 is a multiple. We place the smallest member in this sequence of 5 primes, 71, at a(n=5).
%p A132809 A132809 := proc(n) local i,j ; for i from 2 do if add( ithprime(i+j),j=0..n-1) mod n = 0 then RETURN(ithprime(i)) ; fi ; od: end: seq(A132809(n),n=2..80) ; # _R. J. Mathar_, Nov 27 2007
%Y A132809 Cf. A132810-A132811, A054892.
%K A132809 easy,nonn
%O A132809 2,1
%A A132809 _Enoch Haga_, Sep 01 2007
%E A132809 Edited by _R. J. Mathar_, Nov 27 2007