18421

Appears in sequences

• Numerator of [x^(2n)] of the Taylor series sech(cosec(x)-cot(x)) = 1 -x^2/8 -x^4/128 +x^6/15360 +19*x^8/294912 +25031*x^10/3715891200+... .at n=6A013528
• Decimal part of a(n)^(1/2) starts with a 'nine digits' anagram.at n=8A034277
• Numbers n such that Maple 9.5, Maple 10, Maple 11 and Maple 12 give the wrong answers for the number of partitions of n.at n=10A110375
• Number of base 13 circular n-digit numbers with adjacent digits differing by 8 or less.at n=4A125448
• Fourth powers (n * n * n * n) in carryless arithmetic mod 10.at n=17A169886
• Fourth powers (n * n * n * n) in carryless arithmetic mod 10.at n=31A169886
• a(n) = 109*n^2.at n=13A174339
• Maximum cardinality of a subset of Dyck n-paths p that share both the same area and the same maj(beta(p)) statistic.at n=15A193617
• Integers n such that for all i > n the largest prime factor of i(i+1)(i+2)(i+3)(i+4)(i+5) exceeds the largest prime factor of n(n+1)(n+2)(n+3)(n+4)(n+5).at n=19A193947
• Numbers for which the cube of the sum of the digits is equal to the square of the product of their digits.at n=27A241846
• The index of the first of two consecutive positive triangular numbers (A000217) the sum of which is equal to the sum of three consecutive positive triangular numbers.at n=7A262489
• Number of points of norm <= n in the body-centered cubic lattice with the lattice parameter equal to 2/sqrt(3).at n=15A276648
• Composite numbers k such that b^k == b (mod sigma(k)) for every integer b.at n=2A277286
• Numbers k such that 483*2^k+1 is prime.at n=35A320339
• G.f.: Sum_{k>=0} x^k * Product_{j=1..5*k} (1 + x^j).at n=50A385069