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 A064915 #6 Jun 24 2014 01:08:18 %S A064915 1,2,3,4,5,6,7,8,9,10,12,14,16,18,22,24,26,28,30,36,42,48,54,60,66,72, %T A064915 77,84,90,96,102,108,114,120,126,174,180,210,240,270,300,330,420,630, %U A064915 840,1050,1260 %N A064915 Positive integers n that are not of the form p + q * a^2, where p and q are primes and a is the smallest prime not dividing n. %C A064915 There are no other terms up to 10^7. Conjecture: There are no more terms in the sequence. %t A064915 rep[ n_ ] := Module[ {a, q}, For[ a=2, GCD[ n, a ]!=1, a++, Null ]; For[ q=2, q a^2<n, q++, If[ PrimeQ[ q ]&&PrimeQ[ n-q a^2 ], Return[ True ] ] ]; False ]; Select[ Range[ 1, 10000 ], !rep[ # ]& ] %Y A064915 Cf. A064653. %K A064915 nonn %O A064915 1,2 %A A064915 _Dean Hickerson_, Oct 13 2001