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 A072206 #20 Aug 18 2025 23:36:24
%S A072206 2,4,15,42,176,299,697,988,1794,3683,4526,7807,10701,12384,16262,
%T A072206 23479,32568,36051,47972,57226,62269,79158,91964,113653,147537,166751,
%U A072206 176954,198592,210043,234249,333502,366276,419357,438128,540423,562626,632867
%N A072206 Third terms of triple Peano sequence A071988.
%H A072206 Robert Israel, <a href="/A072206/b072206.txt">Table of n, a(n) for n = 1..10000</a>
%F A072206 Numbers, except 2, satisfy a(n) = 1 + k/3 * (4k^2+5), with k in A005097. - _Ralf Stephan_, Aug 21 2004
%F A072206 a(n) = (n^3+5*n+6)/6, for n+1 prime, so a(n) = A000125(A006093(n)) - _Bert Seghers_, Jan 01 2012, corrected by _Robert Israel_, Jun 20 2019
%p A072206 g:= n -> (n^3+5*n+6)/6:
%p A072206 seq(g(ithprime(i)-1),i=1..100); # _Robert Israel_, Jun 20 2019
%t A072206 seq[n_Integer?Positive] := Module[{fn01 = 1, fn10 = 1, fnout = 1}, Do[{fn10, fn01, fnout} = {fn10 + 1, fn01 + fn10, fn01 + fnout}, {n - 1}]; {fn10, fn01, fnout}]; Ar = Flatten[ Table[ seq[ Prime[n]], {n, 1, 50}]]; a = {}; Do[a = Append[a, Ar[[n]]], {n, 3, 150, 3}]; a
%Y A072206 Cf. A000125, A006093, A071988.
%K A072206 nonn
%O A072206 1,1
%A A072206 _Robert G. Wilson v_, Jul 03 2002