19812

Appears in sequences

• Number of words of length 4 in the n(n-1)/2 transpositions of S[ n ] equivalent to the identity.at n=12A029699
• Number of polyiamonds with n cells that do not tile the plane.at n=13A071333
• Numbers k such that phi(k)*sigma(k) is a cube.at n=11A114077
• a(n) = 1 + (9960 + (6804 + (2464 + (735 + (175 + (21 + n)*n)*n)*n)*n)*n)*n/5040.at n=11A145129
• Numbers n = concat(a,b) such that phi(n) = phi(a) * phi(b), where phi = A000010.at n=31A147619
• Maximal length of rook tour on an n X n+2 board.at n=29A152133
• Number of n X n arrays of squares of integers with every 3X3 subblock summing to 6.at n=3A159206
• Number of n X n arrays of squares of integers with every (n-3)X(n-3) subblock summing to 6.at n=1A159366
• Sum of divisors of cubes.at n=19A175926
• Principal diagonal of the convolution array A212891.at n=11A213436
• Number of paths from (0,1) to (n,2), with vertices (i,k) satisfying 0 <= k <= 3, consisting of segments given by the vectors (1,1), (1,2), (1,-1).at n=16A247355
• a(n) = sigma(sigma(p(n))) = sum of the divisors of the sum of the divisors of number of partitions of n.at n=27A280101
• a(n) = sum of the divisors of the product of the divisors of n.at n=19A280685
• a(n) = A000203(A344422(n)).at n=9A345260
• Expansion of Sum_{k>=0} (k^k * x/(1 - k^k * x))^k.at n=3A355465
• Expansion of Sum_{k>=0} (k^3 * x/(1 - x))^k.at n=3A355496