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 A270792 #7 Apr 06 2016 12:47:52 %S A270792 7,13,23,37,61,73,101,107,139,181,197,239,269,281,313,373,419,433,467, %T A270792 499,521,577,613,653,719,751,761,811,823,853,977,1013,1051,1069,1163, %U A270792 1187,1237,1289,1307,1373,1439,1453,1549,1559,1583 %N A270792 The prime/nonprime compound sequence ABA. %p A270792 # For Maple code for the prime/nonprime compound sequences (listed in cross-references) see A003622. - _N. J. A. Sloane_, Mar 30 2016 %Y A270792 Let A = primes A000040, B = nonprimes A018252. The 2-level compounds are AA = A006450, AB = A007821, BA = A078782, BB = A102615. The 3-level compounds AAA, AAB, ..., BBB are A038580, A049078, A270792, A102617, A270794, A270796, A102216. %K A270792 nonn %O A270792 1,1 %A A270792 _N. J. A. Sloane_, Mar 30 2016