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 A152758 #9 Jan 06 2019 06:06:55 %S A152758 1,8,12,15,24,25,30,32,33,35,36,39,40,42,44,48,50,51,54,56,60,63,65, %T A152758 66,68,69,72,78,80,81,84,85,87,90,92,96,98,100,102,105,108,112,114, %U A152758 116,117,120,121,123,126,128,129,130,132,136,138,140,141,143,144,148,150,153 %N A152758 Numbers k such that the deficiency of k plus the number of proper divisors of k is not a prime number (see A152864). %p A152758 with(numtheory): a := proc (n) if isprime(2*n-sigma(n)+tau(n)-1) = false then n else end if end proc: seq(a(n), n = 1 .. 200); # _Emeric Deutsch_, Jan 08 2009 %Y A152758 Cf. A000005, A000040, A000203, A032741, A033879, A152757, A152770, A152864. %K A152758 easy,nonn %O A152758 1,2 %A A152758 _Omar E. Pol_, Dec 14 2008 %E A152758 Extended by _Emeric Deutsch_, Jan 08 2009 %E A152758 Name edited by _Jon E. Schoenfield_, Jan 06 2019