24020

Appears in sequences

• Number of lines through exactly 2 points of an n X n grid of points.at n=19A018809
• A Chebyshev-related transform of the Fibonacci numbers.at n=15A112576
• a(n) = 1000*n + 20.at n=23A157510
• a(n) = 25*n^2 - 5.at n=30A158446
• Sum of pyramid weights of all Dyck paths of semilength n that have no ascents and no descents of length 1.at n=13A166302
• Smallest number k such that sopf(k)/digsum(k) = prime(n) where sopf(k) is the sum of the distinct primes dividing k and digsum(k) the sum of digits of k.at n=35A241049
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 910", based on the 5-celled von Neumann neighborhood.at n=43A273764
• Number of even parts in the partitions of n into 8 parts.at n=45A309630
• Numbers k for which phi(k) = phi(k''), where phi is the Euler totient function (A000010) and k'' the second arithmetic derivative of k (A068346).at n=41A352331
• Numbers k for which k = phi(k') + phi(k''), where phi is the Euler totient function (A000010), k' the arithmetic derivative of k (A003415) and k'' the second arithmetic derivative of k (A068346).at n=13A352332