21686

Appears in sequences

• 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, 0, 0), (0, -1, 1), (0, 0, 1), (1, 0, 0), (1, 1, -1)}.at n=8A150154
• a(n) = ceiling(A003269(n)/2).at n=36A173674
• a(1) = a(2) = 2; a(n) = a(n-1) + gpf(a(n-2)), where gpf is greatest prime factor.at n=41A258125
• Number of integer partitions of n that can be partitioned into sets with distinct sums.at n=40A381992