4279275

Appears in sequences

• Triangular numbers that can be represented as a product of two triangular numbers greater than 1, and as a product of three triangular numbers greater than 1.at n=22A295769
• Consider the e.g.f. A(x,y) = Sum_{n>=0} Sum_{k=0..n} T(n,k) * x^(2*n-2*k+1) * y^(2*k) / (2*n+1)! and related functions B(x,y) and C(x,y), as defined in the Formula section. Sequence gives the triangular array of coefficients T(n,k) (n>=0, 0<=k<=n) of A(x,y).at n=23A326797
• Triangular numbers with tetrahedral indices: a(n) = (1/72) * (n*(n+1)*(n+2)*(n+3)*(n^2+2)).at n=25A373733
• Odd multiplicative orders of 2+-i modulo primes p == 3 (mod 4).at n=35A385217