25456

Appears in sequences

• "DHK" (bracelet, identity, unlabeled) transform of 1,1,1,1,...at n=20A032245
• Total number of line segments between points visible to each other in a square n X n lattice.at n=16A141255
• A triangle sequence related to the Eulerian numbers of the second kind: t(n,m) = Sum_{i=0..m}(-1)^(m-i)*binomial(n-i-1, m-i)*Stirling2(n+i+1, i+1).at n=38A156363
• Molecular topological indices of the cycle graphs.at n=36A192797
• Numbers n such that n^2+k-1 is the sum of two nonzero squares in exactly k ways for all k = 1, 2, 3.at n=1A273341
• Solution of the complementary equation a(n) = a(n-1) + a(n-2) + b(n-1)*b(n), where a(0) = 1, a(1) = 4, b(0) = 2, b(1) = 3, b(2) = 5, and (a(n)) and (b(n)) are increasing complementary sequences.at n=14A296274
• Numbers k such that e(k) > 1 and k == e(k) (mod lambda(k)), where e(k) = A051903(k) is the maximal exponent in prime factorization of k.at n=19A327295
• a(n) = Sum_{-n<i<n, -n<j<n, gcd{i,j}=2} (n-|i|)*(n-|j|)/8.at n=33A331773
• Primitive terms of A388034.at n=47A388035
• a(n) is the permanent of the square matrix A(n) of order 2*n whose generic entry is A(i, j) = n*(2*i - (-1)^i - 3) + 2*j - (-1)^j/2 + (-1)^i - 3/2 with 1 <= i,j <= 2*n.at n=2A390679