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 A175212 #7 May 02 2014 12:31:51 %S A175212 1,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59,61,67,71,73,79,83,89,97, %T A175212 101,103,107,109,113,127,131,137,139,149,151,157,163,167,173,179,181, %U A175212 191,193,197,199,211,223,227,229,233,239,241,251,257,263,269,271,277,281,283,293 %N A175212 Numbers n such that A000975(n-1)/n is an integer. Also numbers n such that arithmetic mean of the first n Jacobsthal numbers is an integer. %C A175212 Contains the subsequence A066488 and differs therefore from A140475. [From _R. J. Mathar_, Aug 09 2010] %H A175212 R. J. Mathar, <a href="/A175212/b175212.txt">Table of n, a(n) for n = 1..9970</a> %e A175212 Arithmetic mean of partial sums of Jacobsthal numbers is an integer : 0/1=0 n=1; (0+1+1+3+5)/5=2 n=5; (0+1+1+3+5+11+21)/7=6 n=7; (0+1+1+3+5+11+21+43+85+171+341)/11=62 n=11 etc. %Y A175212 Cf. A000975, A001045 %K A175212 easy,nonn %O A175212 1,2 %A A175212 _Ctibor O. Zizka_, Mar 06 2010 %E A175212 Term 34 removed, sequence extended and index in definition corrected by _R. J. Mathar_, Mar 29 2010