27135

Appears in sequences

• a(n) is the concatenation of n and 5n.at n=26A019553
• Triangle read by rows in which row n gives coefficients of polynomial R_n(y) that satisfies R_n(1/3) = 3^n, where R_n(y) forms the initial (n+1) terms of g.f. A057083(y)^(n+1).at n=40A097186
• a(n) = (n-1)*(n+2)*(2*n+11)/2.at n=27A130862
• A sequence of asymptotic density zeta(10) - 1, where zeta is the Riemann zeta function.at n=26A143036
• Array read by rows: row n lists the coefficients of the characteristic polynomial of the n-th principal submatrix of max(2i-j, 2j-i), as in A204154.at n=30A204155
• Numbers n such that n and n+1 both have 20 divisors.at n=3A274361
• p-INVERT of (1,0,1,0,0,0,0,...), where p(S) = 1 - S^3.at n=30A291723
• Numbers k such that both k and k+1 are not exponentially squarefree numbers.at n=19A342188
• Numbers k such that k and k+1 are products of at least 6 primes.at n=40A346207
• G.f. satisfies A(x) = exp( Sum_{k>=1} (2^k + A(x^k)) * x^k/k ).at n=8A362389
• Number of integer partitions of n containing all divisors of all parts.at n=46A371178
• Numbers k such that the odd part of (1+k) divides (1 + odd part of A001615(k)), where A001615 is Dedekind's psi-function.at n=16A387415