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 A066359 #11 Dec 15 2017 17:35:46 %S A066359 46795,78183,112995,1986975,2411175,2689695,2744145,3619071,3712545, %T A066359 4738185,8184715,12176109,13342959,26400843,33789015,40425645, %U A066359 61114185,78464475,83333565,167077575,212066541,248682015,326834725,336828205,353707705,391078425,880254585 %N A066359 Nonsquarefree numbers n such that phi(n) = phi(n-2)-phi(n-1), where phi is Euler's totient function. %C A066359 See comment in A066232. %C A066359 Numbers in A066232 that are not squarefree. %o A066359 (PARI) ph1=1; ph2=1; for(n=3, 880254585, ph3=eulerphi(n); if(issquarefree(n)==0, if(ph3==ph1-ph2, print1(n ", "))); ph1=ph2; ph2=ph3) /* _Donovan Johnson_, Oct 20 2012 */ %K A066359 nonn %O A066359 1,1 %A A066359 _Jason Earls_, Dec 20 2001 %E A066359 a(10)-a(27) from _Donovan Johnson_, Oct 20 2012