18610022

Appears in sequences

• a(n) = 4*a(n-1) - a(n-2) + 1, with a(0) = 0, a(1) = 2.at n=13A001571
• a(n) = A002531(n)*A002531(n+1).at n=13A146983
• Numbers k with property that there is an m = m(k) such that m(m+1)/2 divides k(k+1)/2 and m(k) > m(i) for all i < k.at n=41A309423