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 A369460 #10 Jan 24 2024 13:56:17 %S A369460 0,0,1,1,1,0,2,1,0,1,1,1,2,0,0,1,2,0,0,3,0,2,1,0,1,0,2,2,0,1,2,1,0,0, %T A369460 1,1,2,1,1,1,2,2,2,1,0,1,1,1,0,2,0,2,3,0,2,3,0,1,0,2,1,1,0,2,1,0,1,1, %U A369460 0,3,1,2,1,0,0,3,2,1,1,2,0,1,3,2,1,1,2,1,0,2,2,3,0,1,2,0,4,1,0,2,1,0,0,2,2 %N A369460 Number of representations of 12n-9 as a sum (p*q + p*r + q*r) with three odd primes p <= q <= r. %C A369460 See A369450 for the cumulative sum, and comments there. %H A369460 Antti Karttunen, <a href="/A369460/b369460.txt">Table of n, a(n) for n = 1..100000</a> %F A369460 a(n) = A369055((3*n)-2). %o A369460 (PARI) %o A369460 A369054(n) = if(3!=(n%4),0, my(v = [3,3], ip = #v, r, c=0); while(1, r = (n-(v[1]*v[2])) / (v[1]+v[2]); if(r < v[2], ip--, ip = #v; if(1==denominator(r) && isprime(r),c++)); if(!ip, return(c)); v[ip] = nextprime(1+v[ip]); for(i=1+ip,#v,v[i]=v[i-1]))); %o A369460 A369460(n) = A369054((12*n)-9); %Y A369460 Trisection of A369055. %Y A369460 Cf. A369054, A369248 (gives the positions of 0's in this sequence when nine is added and divided by 12), A369450 (partial sums), A369461, A369462. %K A369460 nonn %O A369460 1,7 %A A369460 _Antti Karttunen_, Jan 23 2024