21037

Appears in sequences

• a(n) = a(n-1) + a(n-4), starting 1,1,1,3.at n=31A014101
• Pseudoprimes to base 63.at n=39A020191
• Number of partitions of n with equal nonzero number of parts congruent to each of 1 and 4 (mod 5).at n=52A035568
• Numbers n such that 205*2^n-1 is prime.at n=22A050854
• A051838 gives numbers m such that the sum of first m primes divides the product of the first m primes. This sequence gives corresponding values of the sum of first m primes.at n=22A140763
• 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, 0), (-1, 1, -1), (-1, 1, 1), (1, 0, -1), (1, 0, 0)}.at n=10A148270
• Where records occur in A179329.at n=15A179997
• Semiprimes in A007504 (the sum of first n primes).at n=26A189072
• Number of non-intersecting unit cubes regularly packed into the tetrahedron of edge length n.at n=57A219965
• Number of partitions of n with difference 6 between the number of odd parts and the number of even parts, both counted without multiplicity.at n=40A242697
• Number of n X 4 0..1 arrays with every element equal to 0, 1, 4 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.at n=14A302676