27965
domain: N
Appears in sequences
- Let S denote the palindromes in the language {0,1,2,3,4}*; a(n) = number of words of length n in the language SS.at n=9A007058
- a(n) = n*(n+1)*(4*n+5)/6.at n=34A016061
- Least k such that first k terms of A022303 contain n more 2's than 1's.at n=18A025518
- Triangle of rooted planar maps, read by rows.at n=48A046652
- Terms of A050530 with four prime divisors.at n=13A053340
- Triangle read by rows: T(n,k) is the number of nonseparable planar maps with 2*n+1 edges and a fixed outer face of 2*k edges which are invariant under a rotation of a 1/2 turn.at n=51A091665
- Ratio of successive row products of triangle A094270: A094273(n+1) / A094273(n).at n=4A094274
- Expansion of 1 / (1 - x - x^2 + x^3 - x^5 + x^15 - x^17 - x^18 + x^19 + x^20).at n=29A174650
- E.g.f. A(x) satisfies: A'(x) = A(x) - 1/A(x) + A(x)^3.at n=6A243952
- Numbers k such that k and k+1 are the product of exactly four distinct primes.at n=30A318896
- Numbers k such that A075255(k) is the square of a prime.at n=23A386954