18513

Appears in sequences

• Pentagonal pyramidal numbers: a(n) = n^2*(n+1)/2.at n=33A002411
• Odd pentagonal pyramidal numbers.at n=8A015223
• Numbers k such that the least term in the periodic part of the continued fraction for sqrt(k) is 16.at n=16A031694
• Least k for which the integers Floor(k/m^2) for m=1,2,...,n are distinct.at n=37A054062
• a(n) = floor(1/(n-1) * Sum_{k=1..n-1} a(k)^(n/k)), given a(0)=1, a(1)=2, a(2)=6.at n=12A079118
• Group the natural numbers such that the n-th group sum is divisible by the n-th triangular number: (1), (2, 3, 4), (5, 6, 7), (8, 9, 10, 11, 12), (13, 14, 15, 16, 17), (18, 19, 20, 21, 22, 23, 24), ... Sequence contains the group sum.at n=32A086500
• G.f.: Product_{i>=1} (1 - 2*(-x)^i)/(1 - (-x)^i)^2.at n=47A104510
• Interlacing n^3/2 and n^2(n + 1)/2.at n=32A130656
• a(n) = (n+1)*(2n+1)^2.at n=16A139757
• Numbers n with property that 4 n^2 are squares arising in A158470.at n=37A158517
• a(n) = 289*n^2 + 17.at n=8A158585
• Maximum value of k^2 * (n-k).at n=50A190798
• Smallest number expressible in the form a^2 + 2b^2, with positive integers a and b, in exactly n ways.at n=8A200977
• a(n) = 17*n^2.at n=33A244630
• Odd numbers of the form (m*k)^2/(m^2-k^2) for distinct integers m and k.at n=18A259288
• 37-gonal numbers: a(n) = n*(35*n-33)/2.at n=33A282852
• Pentagonal pyramidal numbers divisible by 3.at n=22A299412
• Number of n X 6 0..1 arrays with every element equal to 0, 1, 2, 4 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.at n=3A303014
• T(n,k)=Number of nXk 0..1 arrays with every element equal to 0, 1, 2, 4 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.at n=39A303016
• Number of 4Xn 0..1 arrays with every element equal to 0, 1, 2, 4 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.at n=5A303018