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 A174456 #12 Dec 23 2021 21:49:23 %S A174456 735,819,1035,1196,1274,1275,1449,1665,1924,1925,1952,1988,2324,2331, %T A174456 2540,2655,3068,3195,3267,3324,3339,3549,3555,3626,3717,4164,4220, %U A174456 4235,4556,4563,4598,4635,4675,4796,5024,5084,5324,5525,5588,5634,5660,6003 %N A174456 Numbers k such that d(k) = d(k+1) = 12. %H A174456 Zak Seidov, <a href="/A174456/b174456.txt">Table of n, a(n) for n = 1..71998</a> %e A174456 a(1) = 735 = A030630(67) = A030630(68) - 1 = A005237(88); %e A174456 a(2) = 819 = A030630(76) = A030630(77) - 1 = A005237(99); %e A174456 a(3) = 1035 = A030630(100) = A030630(101) - 1 = A005237(124). %t A174456 Select[Range[10^7],DivisorSigma[0,{#,#+1}]=={12,12}&] %t A174456 Transpose[SequencePosition[DivisorSigma[0,Range[6500]],{12,12}]][[1]] (* The program uses the SequencePosition function from Mathematica version 10 *) (* _Harvey P. Dale_, Jul 16 2016 *) %o A174456 (PARI) is(n)=numdiv(n)==12 && numdiv(n+1)==12 \\ _Charles R Greathouse IV_, Jun 19 2016 %Y A174456 Intersection of A005237 and A030630. %K A174456 nonn %O A174456 1,1 %A A174456 _Zak Seidov_, May 25 2010