18824

Appears in sequences

• Numbers k such that 2^k - prime(k) is prime.at n=17A078583
• Number of Pythagorean quadruples mod n; i.e., number of solutions to w^2 + x^2 + y^2 = z^2 mod n.at n=25A096018
• Numbers k such that either 2^k + prime(k) or 2^k - prime(k) is prime.at n=41A130640
• Number of solutions to x^2 + y^2 + z^2 + t^2 == n (mod 2*n) for x,y,z,t in [0, 2*n).at n=12A229294
• Number of maximal 3-independent sets in the 3-dimensional (3, 3, n) grid graph.at n=8A231888
• Number of non-congruent solutions of x^2 + y^2 + z^2 + t^2 == 0 mod n.at n=25A240547
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 81", based on the 5-celled von Neumann neighborhood.at n=30A270100
• Expansion of 1/(1 - x - x^2/(1 + x^2/(1 + x^3/(1 + x^4/(1 + x^5/(1 + ...)))))), a continued fraction.at n=25A302016
• Number of binary words of length n with exactly twice as many occurrences of subword 101 as occurrences of subword 010.at n=17A303430
• Number of non-congruent solutions of x^2+y^2 == z^2+w^2 (mod n).at n=25A316148
• Total surface area of all rectangular prisms with dimensions p X q X q, where p and q are prime, n = p+q and p<q.at n=49A335188
• a(n) = Sum_{k=0..floor(n/2)} (-1)^(k-1)*(k-1)^2*A106828(n, k).at n=9A348208
• Indices of records in A218344.at n=13A354740