87808

Appears in sequences

• Triangle of coefficients in expansion of (2 + 7*x)^n.at n=38A013623
• Numbers of form 4^i*7^j, with i, j >= 0.at n=31A025619
• a(n) = 4*n^3.at n=28A033430
• Numbers whose prime factors are 2 and 7.at n=37A033847
• a(n) = Product{k|n} k^(n/k); product is over the positive divisors of n.at n=13A066841
• Discriminants of integer positive ternary quadratic forms that are spinor regular but not regular.at n=28A094682
• a(1)=2, a(n+1) = a(n)*A010888(a(n)).at n=7A110365
• Modulo 2 recursion switch between A000898 and A121966: A000898 first.at n=11A122018
• Numbers of the form b^m/2 for even b and odd m > 2.at n=36A126032
• a(n) = Product_{k=1..d(n)-1} lcm(b(k), b(k+1)), where b(k) is the k-th positive divisor of n and d(n) = the number of positive divisors of n.at n=27A136182
• G.f.: C(x) = Sum_{n>=0} log(1 - 2^(2n)*x)^(2n)/(2n)!, a power series in x with integer coefficients.at n=5A166995
• Totally multiplicative sequence with a(p) = 2*(3p+1) = 6p+2 for prime p.at n=39A167335
• a(n) = floor(1/{(1+n^4)^(1/4)}), where {} = fractional part.at n=27A184536
• Floor(1/{(8+n^4)^(1/4)}), where {}=fractional part.at n=55A184632
• Numbers having factorization Product_{i=1..m} p(i)^e(i) such that m > 1 and p(i) + e(i) is the same for each i.at n=24A219302
• Number of (n+1) X (1+1) 0..2 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 1 (constant-stress 1 X 1 tilings).at n=6A234436
• Number of (n+1) X (7+1) 0..2 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 1 (constant-stress 1 X 1 tilings).at n=0A234442
• T(n,k) is the number of (n+1) X (k+1) 0..2 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 1 (constant-stress 1 X 1 tilings).at n=21A234443
• T(n,k) is the number of (n+1) X (k+1) 0..2 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 1 (constant-stress 1 X 1 tilings).at n=27A234443
• a(n) is the least number c such that there are exactly n abc-hits with third member c, or 0 if no such c exists.at n=4A272242