31457280

Appears in sequences

• a(n) is the number of occurrences of 7's in the palindromic compositions of 2*n-1, or also, the number of occurrences of 8's in the palindromic compositions of 2*n.at n=20A079861
• Smallest number beginning with 3 and having exactly n prime divisors counted with multiplicity.at n=22A106423
• a(n) = 15*2^n.at n=21A110286
• a(n) = tau(N), where N = the number obtained as a concatenation of 8712 with itself n times and tau(n) = number of divisors of n.at n=35A110754
• G.f.: A(x) = Sum_{n>=0} (2*n+1) * 8^n * x^(n*(n+1)/2).at n=28A111983
• a(n) = 2^(n^2) - 2^(n^2 - n + 1) for n >= 1; a(0) = 0.at n=5A153836
• Expansion of (1-x+4*x^2)/(1-2*x)^2.at n=20A167667
• a(n) = (n-4)*(n-3)*2^(n-2).at n=19A181407
• a(n) = (2n+1)*8^n.at n=7A199301
• Number of n X n 0..7 arrays with no element x(i,j) adjacent to itself or value 7-x(i,j) horizontally, diagonally, antidiagonally or vertically, top left element zero, and 1 appearing before 2 3 4 5 and 6, 2 appearing before 3 4 and 5, and 3 appearing before 4 in row major order (unlabelled 8-colorings with no clashing color pairs).at n=4A233161
• Number of n X 5 0..7 arrays with no element x(i,j) adjacent to itself or value 7-x(i,j) horizontally, diagonally, antidiagonally or vertically, top left element zero, and 1 appearing before 2 3 4 5 and 6, 2 appearing before 3 4 and 5, and 3 appearing before 4 in row major order (unlabelled 8-colorings with no clashing color pairs).at n=4A233165
• T(n,k)=Number of nXk 0..7 arrays with no element x(i,j) adjacent to itself or value 7-x(i,j) horizontally, diagonally, antidiagonally or vertically, top left element zero, and 1 appearing before 2 3 4 5 and 6, 2 appearing before 3 4 and 5, and 3 appearing before 4 in row major order (unlabeled 8-colorings with no clashing color pairs).at n=40A233168
• Number of edges in geodesic dome generated from icosahedron by recursively dividing each triangle in 4.at n=11A277451
• Decimal representation of the diagonal from the origin to the corner of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 81", based on the 5-celled von Neumann neighborhood.at n=24A285654
• Decimal representation of the diagonal from the origin to the corner of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 213", based on the 5-celled von Neumann neighborhood.at n=24A286733
• Decimal representation of the diagonal from the origin to the corner of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 267", based on the 5-celled von Neumann neighborhood.at n=24A287463
• Decimal representation of the diagonal from the origin to the corner of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 326", based on the 5-celled von Neumann neighborhood.at n=27A287713
• Decimal representation of the diagonal from the origin to the corner of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 339", based on the 5-celled von Neumann neighborhood.at n=24A287741
• a(n) is the least number of the form p^2 + q^2 - 2 for primes p and q that is an odd multiple of 2^n, or -1 if there is no such number.at n=21A359439
• a(n) is the least positive number with distinct decimal digits and n prime factors, counted with multiplicity, or -1 if there is no such number.at n=23A364040