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A263251 Odd bisection of A263087; number of solutions to x - d(x) = (2n+1)^2, where d(x) is the number of divisors of x (A000005).

%I A263251 #13 Nov 09 2015 16:06:41
%S A263251 2,1,0,0,2,1,1,1,1,1,2,1,1,0,1,2,1,0,0,1,1,1,1,0,1,1,1,1,1,0,1,1,1,0,
%T A263251 1,2,0,1,1,1,1,1,0,1,0,2,1,0,1,1,1,0,3,1,1,1,1,1,1,1,1,3,0,0,1,2,2,0,
%U A263251 2,1,0,1,1,1,2,1,1,0,1,1,0,1,1,1,1,3,2,1,0,1,1,1,1,3,1,1,1,1,1,0,1,1,0,0,2,0,0,0,0,1,2,2,2,2,0,0,1,0,1,1,1
%N A263251 Odd bisection of A263087; number of solutions to x - d(x) = (2n+1)^2, where d(x) is the number of divisors of x (A000005).
%H A263251 Antti Karttunen, <a href="/A263251/b263251.txt">Table of n, a(n) for n = 0..10000</a>
%F A263251 a(n) = A263087(2*n + 1).
%o A263251 (PARI)
%o A263251 A060990(n) = { my(k = n + 2400, s=0); while(k > n, if(((k-numdiv(k)) == n),s++); k--;); s}; \\ Hard limit A002183(77)=2400 good for at least up to A002182(77) = 10475665200.
%o A263251 A263087(n) = A060990(n^2);
%o A263251 A263251(n) = A263087((2*n)+1);
%o A263251 p = 0; for(n=0, 10000, k = A263251(n); p += k; write("b263251.txt", n, " ", k); write("b263253.txt", n, " ", p)); \\ Compute A263251 and A263253 at the same time.
%o A263251 (Scheme) (define (A263251 n) (A263087 (+ n n 1)))
%Y A263251 Cf. A000005, A060990, A263087, A263250.
%Y A263251 Cf. also A263253 (partial sums).
%K A263251 nonn
%O A263251 0,1
%A A263251 _Antti Karttunen_, Nov 07 2015