618496

Appears in sequences

• Number of elements of order <= 2 in group of n X n upper triangular matrices over GF(2).at n=7A008964
• a(n) = T(n,2), array T as in A049600.at n=15A049611
• Binomial transform of binomial(n+2,2).at n=14A084851
• Number of nX5 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 1 0 and 1 1 1 vertically.at n=14A209221