20159

Appears in sequences

• Least m which can be written as i*j+i+j in n different ways: A072670(m)=n.at n=41A072671
• Prime(n)*prime(2*n)+prime(n)+prime(2*n).at n=23A072672
• Odd numbers n for which 17 is the smallest i (>= 1) with Jacobi symbol J(i,n) getting either a value 0 or -1.at n=23A112077
• a(n)= numerator of ((n + 3)! - (n - 3)!)/(n!).at n=2A127227
• Numbers k such that either k or k+1 is divisible by the numbers from 1 to 10.at n=30A131663
• a(n) = n!/2 - 1.at n=6A139172
• a(n) is the number of numbers removed in each step of Eratosthenes's sieve for 8!.at n=0A145535
• Composites c where |c-m| = 1, where m is any of the smallest positive integers with their number of divisors. (m belongs to sequence A007416.)at n=43A152246
• a(n) = 576*n - 1.at n=34A158372
• Numbers m such that m mod k is k-1 for all k = 2..9.at n=7A166931
• a(n) = 4*n! - 1.at n=7A173321
• a(1)=1. a(n) = the smallest integer > a(n-1) such that d(a(n))+d(a(n)+1) > d(a(n-1))+d(a(n-1)+1), where d(m) = the number of divisors of m.at n=38A175143
• Smallest number requiring n terms to be expressed as a sum of factorials.at n=24A200748
• Smallest number m such that A226460(m) = n.at n=22A226462
• a(n) is the smallest number k representable as x*y+x+y, where x>=y>1, in exactly n ways, or -1 if no such k exists.at n=39A253975
• Sequence defined by a(1)=a(2)=1 and a(n) = gray(a(n-1)) + gray(a(n-2)), with gray(m) = A003188(m).at n=15A265387
• Numbers k such that k and k+1 are both divisible by the total binary weight of their divisors (A093653).at n=9A338514
• Numbers k achieving record deficiency via a residue-based measure, M(k) = (k+1)*(1 - zeta(2)/2) - 1 - ( Sum_{j=1..k} k mod j )/k.at n=16A362082