225456

Appears in sequences

• Triangular numbers which are 8-almost primes.at n=22A076582
• Partial sums of dodecahedral numbers (A006566).at n=21A116689
• Number of -3..3 arrays x(i) of n+1 elements i=1..n+1 with set{t,u,v in 0,1}((x[i+t]+x[j+u]+x[k+v])*(-1)^(t+u+v)) having three, four or five distinct values for every i,j,k<=n.at n=16A211724
• Positive numbers m such that m^2 - 1 divides 2^m - 1.at n=25A247219
• Positive numbers m such that m^2 - 1 divides 4^m - 1.at n=44A271842
• Triangular numbers k such that phi(k) is a square number, where phi(k) is the Euler totient function (A000010).at n=16A287473
• Triangular numbers that are the sum of two distinct nonzero triangular numbers in exactly two ways.at n=28A350368