40008

Appears in sequences

• Numbers k such that the least term in the periodic part of the continued fraction for sqrt(k) is 50.at n=7A031728
• Numbers k such that the number of primes between k and 2k (inclusive) is equal to the number of primes between k and reverse(k) (inclusive).at n=34A074814
• Total number of triangles in all polyiamonds with n triangles.at n=11A096361
• Triangle read by rows: T(n,k) is number of paths from (0,0) to (3n,0) that stay in the first quadrant (but may touch the horizontal axis), consisting of steps u=(2,1),U=(1,2), or d=(1,-1) and having sum of the heights of its pyramids equal to k (a pyramid is a sequence u^pd^p or U^pd^(2p) for some positive integer p, starting at the x-axis; p is the height of the pyramid).at n=50A109157
• Numbers k such that k and k^2 use only the digits 0, 1, 4, 6 and 8.at n=48A136861
• Triangle read by rows, coefficients of the polynomials P(k, x) = (1/2) Sum_{p=0..k-1} Stirling2(k, p+1)*x^p*(1-4*x)^(k-1-p)*(2*p+2)!/(p+1)!.at n=30A142963
• a(n) = 64*n^2 + 8.at n=24A158488
• Irregular table read by rows: Take a diagonal-edged (or diamond-shaped) checkerboard with all diagonals drawn, as in A333434. Then T(n,k) = number of k-sided polygons in that figure for k >= 3.at n=39A333458
• Numbers whose palindromization is a perfect power.at n=27A342942