39636

Appears in sequences

• Numbers n such that n and its digit reversal R(n) both are difference of positive cubes.at n=38A109879
• Number of 2 X 2 matrices having all terms in {1,...,n} and nonnegative even determinant.at n=18A211066
• p-INVERT of (1,1,0,0,0,0,...), where p(S) = 1 - S - 2 S^2 + S^3.at n=11A291412
• The sum of the first n terms of the sequence is the concatenation of the first n digits of the sequence, and a(1) = 4.at n=4A299867
• Expansion of (1/(1 - x))*Product_{k>=1} (1 - x^(3*k))/(1 - x^k).at n=40A304630
• Numbers k such that sigma(k)! - 1 is prime, where sigma is A000203.at n=22A309548
• a(n) is the number of 5 element sets of distinct integer-sided trapezoids whose base angles are 60 degrees that fill an equilateral triangular grid of side n units with a trapezoid filled by 3 trapezoids.at n=31A391204