63700

Appears in sequences

• a(n) = binomial(n,3)*binomial(n-1,3)/4.at n=12A006542
• House numbers (version 2): a(n) = (n+1)^3 + (n+1)*Sum_{i=0..n} i.at n=34A050509
• Triangle T(n,k) defined by Sum_{1<=k<=n} T(n,k)*u^k*t^n/n! = exp(((1-t)*(1-t^2)*(1-t^3)...)^(-u)-1).at n=25A066045
• OU-Sigma multiperfect numbers.at n=9A091321
• Corresponding values of arithmetic means of divisors of numbers from A007340.at n=30A157848
• a(n) = binomial(m+n-1,n)^2 - binomial(m+n,n+1)*binomial(m+n-2,n-1) with m = 14.at n=3A169937
• Numbers n for which the terms of the multiplicative sequence {n^2/A049417(n)} are integers.at n=35A185288
• Degrees of irreducible representations of simple Chevalley group F4(2).at n=12A214481
• Number of unrestricted planar Langford sequences.at n=19A304271
• Exponential weird numbers: numbers that are exponential abundant (A129575) but not exponential pseudoperfect (A318100).at n=3A321146
• Numbers k such that k and usigma(k) have the same set of prime divisors, where usigma(k) is the sum of unitary divisors of k (A034448).at n=26A329858
• Coreful weird numbers: numbers k that are coreful abundant (A308053) but no subset of their aliquot coreful divisors sums to k.at n=3A339939
• The number of vertices on a concave circular triangle formed by the straight line segments mutually connecting all vertices and all points that divide the sides into n equal parts.at n=19A340686
• Triangle read by rows: T(n,k) = generalized binomial coefficients (n,k)_12 (n >= 0, 0 <= k <= n).at n=17A342891
• Triangle read by rows: T(n,k) = generalized binomial coefficients (n,k)_12 (n >= 0, 0 <= k <= n).at n=18A342891
• a(n) is the smallest positive integer which can be represented as the sum of distinct nonzero dodecahedral numbers in exactly n ways, or -1 if no such integer exists.at n=26A360216