21237

Appears in sequences

• Number of ordered quadruples of integers from [ 1,n ] with no common factors between triples.at n=28A015635
• Output of the linear congruential pseudo-random number generator rand() used in Microsoft's Visual C++.at n=36A096558
• G.f.: x^2/((1-x^2)^2*Product_{i>0}(1-x^i)).at n=28A103650
• Number of base 15 circular n-digit numbers with adjacent digits differing by 2 or less.at n=6A124893
• Numbers k such that (k!-9)/9 is prime.at n=21A139204
• 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), (0, 1, -1), (1, 0, 1)}.at n=9A148956
• a(n) is the smallest number which is the sum of two positive n-gonal numbers in more than one way.at n=17A199809
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 609", based on the 5-celled von Neumann neighborhood.at n=27A273210
• Number of (binary) max-heaps on n elements from the set {0,1} containing exactly nine 0's.at n=20A326510
• Expansion of e.g.f. 1/(exp(x) - x/(1 - x)).at n=7A352294
• A382168 with duplicates removed.at n=36A382169