18450

Appears in sequences

• Number of asymmetric mobiles (circular rooted trees) with n nodes and 3 leaves.at n=28A055364
• Numbers k such that 3*2^k - 5 is prime.at n=38A057912
• Number of orbits of length n under the map whose periodic points are counted by A000984.at n=9A060165
• a(n) = (3+n)*(2 + 33*n + n^2)/6.at n=38A101860
• Column 9 of array illustrated in A089574 and related to A034261.at n=4A109820
• Column 11 of table A105552.at n=8A110554
• (1/4)*number of nonsquare rectangles with corners on an n X n grid of points.at n=18A122225
• Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 1), (-1, 1, 0), (0, 1, 0), (1, -1, 1), (1, 1, -1)}.at n=9A148435
• Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 1), (-1, 0, 1), (-1, 1, 1), (1, 0, -1), (1, 0, 0)}.at n=9A148758
• a(n) = n*(5*n^2-8*n+5)/2.at n=20A226449
• a(n) is the smallest number whose Collatz ('3x+1') trajectory crosses its initial value exactly n times.at n=52A301937
• Matrix product of triangle of Stirling numbers of second kind A008277 and square of unsigned Lah triangle A105278.at n=17A308440
• a(n) is the number of words of length n over the alphabet {a,b,c} with an even number of appearances of the letter 'a' and the sum of appearances of the letters 'b' and 'c' add up to at most 3.at n=25A341896