635628

Appears in sequences

• a(n) = smaller member of n-th pair of distinct, positive, triangular numbers whose sum and difference are also triangular numbers.at n=33A185129
• a(n) = binomial(8*n+2,n)/(4*n+1).at n=6A234461
• a(0) = 1; a(n) = Sum_{k=0..floor((n-1)/7)} a(7*k) * a(n-1-7*k).at n=43A386396