22919

Appears in sequences

• a(n) = n*(n+2)*(n-2)/3.at n=39A077415
• Least area/6 of primitive Pythagorean triangles with even leg 4n.at n=40A096898
• Number of different strings of length n+4 obtained from "123...n" by iteratively duplicating any substring.at n=22A137741
• a(n) = (2*n+1)*(2*n+3)*(2*n+5)/3.at n=19A162540
• Riordan array (((1+x)/(1-x-x^2))^m, x*A000108(x)), m=2.at n=57A185676
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 221", based on the 5-celled von Neumann neighborhood.at n=31A270936
• Nonsemiprimes in A306097 = A121707 \ A267999.at n=31A321488