211250

Appears in sequences

• Numbers that are the sum of 2 distinct nonzero squares in exactly 7 ways.at n=3A025308
• Numbers k that divide 9^k + 7^k.at n=35A045605
• Antichains (or order ideals) in the poset 2*3*3*n or size of the distributive lattice J(2*3*3*n).at n=3A056935
• Number of antichains (or order ideals) in the poset 3*3*3*n or size of the distributive lattice J(3*3*3*n).at n=2A056937
• A014486-encoding of plane binary trees (Stanley's d) whose interior zigzag-tree (Stanley's c, i.e., tree obtained by discarding the outermost edges of the binary tree) is isomorphic to a valid plane binary tree (Stanley's d).at n=11A080299
• a(n) = n^2*(n+1)^2/2.at n=25A163102
• Smallest number that can be written in exactly n ways as sum of two quarter-squares.at n=25A240952
• Rhonda numbers in vigesimal number system.at n=31A255732
• Number of 2 X 2 matrices with all elements in 0..n such that the sum of the elements is prime.at n=30A281550
• a(n) is the smallest nonnegative integer k where exactly n ordered pairs of positive integers (x, y) exist such that x^2 + y^2 = k.at n=15A328151
• Primitive integers for the number of ways k to write as a sum of two squares.at n=44A336542
• Square array read by antidiagonals upwards: T(i,j), i, j >= 1, is the smallest number m such that the symmetric presentation of sigma, SRS(m), has maximum width 3, consists of 2*i-1 parts and has 2*j-1 occurrences of maximum width 3 in its width pattern (row m of A341969).at n=8A377668