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 A145748 #13 Aug 03 2014 14:37:23 %S A145748 2,854,751358,1421637,8775206,8892195,16485944,31845344,95494035, %T A145748 277653495,380438505,744048855,1091725394,1615353002,2284844925, %U A145748 2491028745,6345217034,8490513014,12784909335,14177454885,15669084375,17694356295,17836667354,24180347115 %N A145748 Numbers n such that phi(n+1)-phi(n)=sigma(n+1)-sigma(n). %C A145748 This sequence is a subsequence of A066198. %t A145748 de[n_]:=DivisorSigma[1,n]-EulerPhi[n];Do[If[de[n]==de[n+1],Print[n]],{n,50000000}] (* Firoozbakht *) %t A145748 Select[Range[10^6], (EulerPhi[# + 1] - EulerPhi[#]) == (DivisorSigma[1, # + 1] - DivisorSigma[1, #]) &] (* _Alonso del Arte_, Feb 08 2012 *) %Y A145748 Cf. A066198, A145749. %K A145748 nonn %O A145748 1,1 %A A145748 _Farideh Firoozbakht_, Nov 01 2008 %E A145748 a(9)-a(16) from _Donovan Johnson_, Dec 14 2009 %E A145748 a(17)-a(24) from _Donovan Johnson_, Feb 08 2012