19109
domain: N
Appears in sequences
- Numbers whose base-2 representation has exactly 13 runs.at n=18A043580
- Smallest solution m to (n+1)*phi(m) = n*sigma(m), or -1 if no solution exists.at n=31A065824
- a(n) = A065824(A047845(n+1)).at n=14A065884
- Diagonal of array A085205.at n=18A085228
- Semiprimes that are the sum of the first n semiprimes for some n.at n=28A092190
- Sequence is {a(0,n)}, where a(m,0)=1, a(m,n) = a(m,n-1) + a(m-1,n), a(0,n+1) = a(n,n).at n=8A110576
- a(n) = 1 + n + ((n-1)*n^2)/2.at n=34A218152
- Number of cyclotomic cosets of 11 mod 10^n.at n=48A220021
- Numbers of the form p*q, p and q prime with q=2*p+3.at n=13A226754
- Number of ways to fill a Young diagram with positive integers summing to n such that all rows and columns are strictly increasing.at n=31A323451
- Odd composite integers m such that A052918(m-J(m,29)) == 0 (mod m) and gcd(m,29)=1, where J(m,29) is the Jacobi symbol.at n=27A340095
- Number of integer partitions of n with more than one mode.at n=47A362607