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 A064970 #11 Jun 24 2014 01:16:21 %S A064970 1,2,3,6,7,18,19,23,33,34,38,66,67,77,101,102,110,111,113,114,115,119, %T A064970 120,129,133,134,136,172,173,185,189,190,192,193,196,224,225,235,287, %U A064970 288,306,307,339,340,352,367,405,406,420,452,453,465,466 %N A064970 a(1)=1; thereafter, values of n for which r(n)-r(n-1) and r(n-1)-r(n-2) have the same sign, where r(n) = A005132(n). %H A064970 <a href="/index/Rea#Recaman">Index entries for sequences related to Recamán's sequence</a> %e A064970 E.g., going from r(4)=2 to r(5)=7 to r(6)=13 we increase twice in a row, so 6 is a member. Going from r(21)=63 to r(22)=41 to r(23)=18 we decrease twice in a row, so 23 is a member. %Y A064970 Cf. A005132. %K A064970 nonn %O A064970 1,2 %A A064970 _Allan Wilks_, Oct 30 2001 %E A064970 Better description from _Dean Hickerson_, Feb 15 2006