23020

Appears in sequences

• T(2n,n+3), T given by A026758.at n=6A026874
• Number of asymmetric mobiles (circular rooted trees) with n nodes and 4 leaves.at n=14A055365
• A064637 converted to factorial base.at n=26A064477
• Number of 6X6 arrays of squares of integers, symmetric about both diagonal and antidiagonal, with all rows summing to n.at n=34A156389
• Number of n X n arrays of squares of integers, symmetric about both diagonal and antidiagonal, with all rows summing to 34.at n=4A156496
• a(n) = 1000*n + 20.at n=22A157510
• a(n) = (n+1)*(n^3+15*n^2+74*n+132)/12.at n=19A217947
• Sequence A261220 shown in factorial base: a(n) = A007623(A261220(n)).at n=43A260743
• Triangle read by rows: T(n,k) (n >= 1, 1 <= k <= n) = number of normalized 2n-plets associated to trees with k edges.at n=32A294439
• a(n) = (Sum_{k=0..n-1} (-1)^k * (4k+1) * 160^(n-1-k) * C(2k,k) * Sum_{j=0..k} C(k,j) * C(k+2j,2j) * C(2j,j) * (-20)^(k-j)) / (n * C(2n,n)).at n=2A337247
• Numbers k such that there are exactly four biquadratefree powerful numbers (A338325) between k^2 and (k+1)^2.at n=18A338391
• The sum of the numbers on the perimeter of the n X n diamond frame, located at the top of the numerical pyramid containing the positive integers in natural order.at n=20A359096
• Triangular array T(n,k), read by rows: coefficients of strong divisibility sequence of polynomials p(1,x) = 1, p(2,x) = 2 + 5*x, p(n,x) = u*p(n-1,x) + v*p(n-2,x) for n >= 3, where u = p(2,x), v = 1 - 2*x - x^2.at n=30A367299
• Array read by antidiagonals: T(m,n) (m >= 1, n >= 1) = number of reduced connected row convex (RCRC) constraints between an m-element set and an n-element set.at n=40A372066