19171

Appears in sequences

• a(n) = 3^n - 2^n.at n=9A001047
• a(n) is the concatenation of n and 9n.at n=18A009474
• Nexus numbers (n+1)^9-n^9.at n=2A022525
• Triangle T(n,k) (0 <= k <= n) giving number of chains of length k in partially ordered set formed from subsets of n-set by inclusion.at n=46A038719
• Nonprimes k such that k divides 3^(k-1) - 2^(k-1).at n=34A073631
• Smallest multiple of n beginning with n and having a digit sum n, or 0 if no such number exists.at n=18A077727
• Square array T(n,k) of second binomial transforms of generalized Fibonacci numbers, read by ascending antidiagonals, with n, k >= 0.at n=54A083861
• G.f.: (2-x)/((1+2x)(1-3x)); e.g.f.: exp(3x)+exp(-2x); a(n)=3^n+(-2)^n.at n=9A087451
• Triangle read by rows: T(n,k) = number of distinct lines through the origin in the n-dimensional cubic lattice of side length k with one corner at the origin.at n=75A090030
• Matrix defined by a(n,k) = 3^n*Fibonacci(k) - 2^n*Fibonacci(k-2), read by antidiagonals.at n=56A090888
• Semiprimes of the form 3^n - 2^n.at n=2A095027
• Cumulative sum of absolute values of coefficients of q^(2n) in the series expansion of Ramanujan's mock theta function f(q).at n=35A109471
• a(n) = concatenation of (n times each digit of n).at n=18A111704
• Triangle read by rows: T(n,k) = Sum_{j=0..n} binomial(n, k+j)*2^(n-k-j).at n=46A112626
• a(n) = 3^(n^2) - 2^(n^2).at n=3A120801
• Numbers with sum of digits = 19, divisible by 19 and containing the string "19".at n=1A121669
• Triangle read by rows: T(n,k) = number of specially labeled bicolored connected graphs with k points in one color class and n-k points in the other class . "Special" means there are separate labels 1,2, ...,k and 1,2, ...,n-k for the two color classes (n >= 1, k = floor((n+1)/2), ..., n).at n=38A123260
• Triangle read by rows: T(n,k) = p(k)*T(n-1,k) + T(n-1,k-1) (1 <= k <= n), where p(k) denotes the k-th prime.at n=46A124960
• Triangle read by rows: matrix product of the Stirling numbers of the second kind with the binomial coefficients.at n=53A126351
• This is to A139025 as A139025 to A014688, see A139025 for details.at n=31A139026