19104

Appears in sequences

• a(n) = s(1)s(n) + s(2)s(n-1) + ... + s(k)s(n+1-k), where k = [ (n+1)/2 ], s = (composite numbers).at n=42A024588
• Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 69.at n=31A031567
• Number of nonnegative solutions of x1^2 + x2^2 + ... + x9^2 = n.at n=30A045851
• a(n) = Sum{T(n,i): i=0,1,...,n}, where T is given by A048113.at n=18A048114
• Sum_{k<=n} (sigma(k)^2), where sigma(k) denotes the sum of the divisors of k A000203.at n=26A072379
• Numbers k for which 8*k+1, 8*k+5, 8*k+7 and 8*k+11 are primes.at n=28A123983
• Number of n X n arrays of squares of integers summing to 30.at n=1A159425
• Number of 7-step E, S, NW and NE-moving king's tours on an n X n board summed over all starting positions.at n=5A187590
• Number of partitions of n such that no part is a sum of two other parts.at n=50A236912
• Number of partitions p of n such that (number of distinct parts of p) < max(p) - min(p).at n=37A239954
• Triangle of numbers where T(n,k) is the number of k-dimensional faces on a partially truncated n-cube, 0 <= k <= n.at n=51A271316
• Numbers n such that the decimal number concat(7,n) is a square.at n=28A273362
• Wiener index of the n X n white bishop graph.at n=15A292059
• a(n) is the greatest integer k such that k/Fibonacci(n) < 2/3.at n=23A293545
• G.f.: Sum_{n>=0} (x^(n+1) + i)^n / (1 + i*x^n)^(n+1), in which the constant term is taken to be 1.at n=47A323690
• Number of integer partitions of n with frequency depth floor(sqrt(n)).at n=40A325252
• Number of integer partitions of n with the maximum adjusted frequency depth for partitions of n.at n=40A325254
• Number of integer partitions of n with frequency depth round(sqrt(n)).at n=40A325271
• Number of Hamiltonian labeled n-vertex digraphs (with loops).at n=4A326204
• a(n) = greatest number in row n of the array in A225485.at n=39A364810