20195

Appears in sequences

• Numbers that are the sum of 5 nonzero 8th powers.at n=17A003383
• Numbers that are the sum of 2 positive 9th powers.at n=4A003391
• Numbers that are the sum of at most 2 positive 9th powers.at n=8A004886
• Numbers that are the sum of at most 3 positive 9th powers.at n=13A004887
• Numbers that are the sum of at most 4 positive 9th powers.at n=19A004888
• Numbers that are the sum of at most 5 positive 9th powers.at n=26A004889
• Numbers that are the sum of at most 6 positive 9th powers.at n=34A004890
• a(n) = 2^n + 3^n.at n=9A007689
• Geometric mean of phi(n) and sigma(n) is an integer, n odd.at n=35A015705
• Centered cube numbers: a(n) = (n+1)^9 + n^9.at n=2A036087
• Composite numbers whose prime factors contain no digits other than 5 and 7.at n=29A036320
• Sum of next n 9th powers.at n=1A075670
• Expansion of (1 - 3*x + x^2)/((1-2*x)*(1-3*x)).at n=10A085281
• a(n) = 15 + floor((2 + Sum_{j=1..n-1} a(j))/3).at n=25A120159
• a(n) = 3^(n^2) + 2^(n^2).at n=3A120800
• a(n) = 2^(2*n+1) + 3^(2*n+1).at n=4A138233
• Table T(k,n) read along antidiagonals: sum of the k-th powers of the distinct prime factors of A024619(n).at n=36A138296
• Triangle read by rows, X^n * [1,0,0,0,...]; where X = a tridiagonal matrix with (1,1,1,...) in the main and subsubdiagonals and (1,2,3,...) in the subdiagonal.at n=54A140734
• Integers n such that 6n, 36n, and 216n fall between pairs of twin primes, that is, 6n-1, 6n+1, 36n-1, 36n+1, 216n-1, and 216n+1 are prime.at n=14A192851
• T(n,k)=Number of (n+1)X(n+1) -k..k symmetric matrices with every 2X2 subblock having sum zero.at n=43A210694