22426

Appears in sequences

• Numbers k such that the continued fraction for sqrt(k) has odd period and if the last term of the periodic part is deleted the two central terms are both 19.at n=7A031607
• Decimal part of cube root of a(n) starts with 2: first term of runs.at n=27A034128
• a(n) is the number of divisors of n-th even perfect number.at n=22A061645
• Number of unrooted directed trees on n nodes with a red root.at n=5A097630
• Numbers m such that (1+i)^m - i is a Gaussian prime.at n=27A103329
• Sequence is {a(2,n)}, where a(m,n) is defined at sequence A111518.at n=11A111520
• Semiprimes in A054556.at n=21A113693
• 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), (0, -1, 1), (0, 0, 1), (1, 1, 0)}.at n=8A150231
• Number of (n+1) X 4 0..1 arrays with column and row pair sums b(i,j)=a(i,j)+a(i,j-1) and c(i,j)=a(i,j)+a(i-1,j) nondecreasing in column and row directions, respectively.at n=21A204646
• Number of n X 2 nonnegative integer arrays with upper left 0 and lower right n+2-4 and value increasing by 0 or 1 with every step right or down.at n=24A252870