22809

Appears in sequences

• Number of ordered quadruples of integers from [ 2,n ] with no common factors between triples.at n=29A015639
• Numbers whose base-7 representation contains exactly four 3's.at n=32A043408
• Number of permutations of length n which avoid the patterns 1342, 3421, 4213.at n=9A116802
• a(n) is the number of integers k less than 10^n such that the decimal representation of k lacks the digit 1, at least one of digits 2,3, at least one of digits 4,5, at least one of digits 6,7 and at least one of digits 8,9.at n=4A126641
• Semiprimes q such that q^2-4 and q^2+4 are also semiprimes.at n=21A173084
• Dispersion of (floor(n*e)), by antidiagonals.at n=56A191455
• Number of zero-sum -n..n arrays of 4 elements with first through third differences also in -n..n.at n=30A202512
• Decimal representation of the x-axis, from the left edge to the origin, of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 531", based on the 5-celled von Neumann neighborhood.at n=16A282952
• G.f. A(x) = Sum_{n>=0} a(n)*x^n satisfies A(x) = 1/(1 - x^a(1) - x^a(2)/(1 - x^a(3) - x^a(4)/(1 - x^a(5) - x^a(6)/(1 - ... )))), a continued fraction.at n=19A293855
• Expansion of e.g.f. exp(3*(exp(x) - 1 - x)).at n=8A367890