43661

Properties

Appears in sequences

• a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n-k+1), where k = [ n/2 ], s = (natural numbers), t = (F(2), F(3), F(4), ... ).at n=17A024861
• a(n) = (2^(2+n)-(-1)^n)/3 - 2*n.at n=15A141025
• Primes of the form x^2 + 7*y^2, where x and y=x+1 are consecutive natural numbers.at n=34A176616
• Number of 2 X 2 matrices having all terms in {1,...,n} and determinant >= n.at n=17A211061
• Number of forests of rooted plane binary trees (all nodes have outdegree of 0 or 2) with n total nodes.at n=22A222006
• Primes such that prime plus its digit sum is a perfect square.at n=19A230087
• Number of (n+1) X (5+1) 0..1 arrays with every 2 X 2 subblock antidiagonal maximum minus diagonal minimum nondecreasing horizontally and diagonal maximum minus antidiagonal minimum nondecreasing vertically.at n=28A253394
• Number of active (ON, black) cells at stage 2^n-1 of the two-dimensional cellular automaton defined by "Rule 529", based on the 5-celled von Neumann neighborhood.at n=7A272747
• Primes equal to a hexagonal number plus 1.at n=35A285790
• Primes equal to a centered 9-gonal number plus 1.at n=23A285812
• Prime numbersat n=4550