121404

Appears in sequences

• Number of fib000 primes (A095085) in range ]2^n,2^(n+1)].at n=22A095065
• Number of 2 X 2 nonsingular 0..n matrices with a(1,1) <= a(1,2) <= a(2,1) <= a(2,2).at n=38A183763
• Auxiliary r(n) sequence used to prove some properties about Rowland's sequence: r(1) = 1, and r(n) = 1/2*(c(n)+1), where c(n) is A190894, for n>1.at n=47A190895
• Number of 4Xn 0..1 arrays with every element equal to 0 or 1 horizontally or antidiagonally adjacent elements, with upper left element zero.at n=21A301793