18109

Appears in sequences

• Strong pseudoprimes to base 92.at n=26A020318
• Shifts left under COMPOSE transform with itself.at n=9A030266
• Fibonacci iteration starting with (1, a(n)) leads to a "nine digits anagram".at n=26A034587
• T(n,n-6), where T is the array in A055830.at n=12A055833
• A simple recurrence with one error.at n=7A090805
• Numbers k such that 9*10^k + 7 is prime.at n=23A096774
• Number of permutations containing 3241 patterns only as part of 35241 patterns.at n=8A110447
• Least k such that 10^n + k is a Sophie Germain prime and the lesser of a twin prime pair.at n=14A118580
• Convolution triangle of A030266, which shifts left under self-COMPOSE.at n=36A125278
• Rectangular table, read by antidiagonals, where the g.f.s of row n, R(x,n), satisfy: R(x,n+1) = R(G(x),n) for n>=0 and x*R(x,0) = G(x) = x + x*G(G(x)) is the g.f. of A030266.at n=44A128325
• Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 1001-1111 pattern in any orientation.at n=11A146621
• Number of n X n binary arrays symmetric about the diagonal and under 90 degree rotation with all ones connected only in a 1001-1111 pattern in any orientation.at n=24A146623
• Partial sums of A048995.at n=51A174514
• Number of nondecreasing -3..3 vectors of length n whose dot product with some lexicographically greater or equal nondecreasing -3..3 vector equals n.at n=11A226417
• Number of length 2+3 0..n arrays with every four consecutive terms having the maximum of some two terms equal to the minimum of the remaining two terms.at n=11A249708
• Number of integer partitions of n with exactly two distinct multiplicities.at n=43A325243
• a(n) = n*a(n-1) + n^signum(n mod 4), a(0) = 1.at n=7A344229
• G.f. A(x,y) satisfies: -y = f(-x,-A(x,y)), where f(x,y) = Sum_{n=-oo..oo} x^(n*(n+1)/2) * y^(n*(n-1)/2) is Ramanujan's theta function.at n=54A354650
• a(n) = A354650(n,2*n), for n >= 0.at n=6A354660
• Square array A(n,k), n >= 0, k >= 0, read by antidiagonals downwards, where column k is the expansion of B(x)^k, where B(x) is the g.f. of A110447.at n=53A379598