20591
domain: N
Appears in sequences
- Pseudoprimes to base 17.at n=40A020145
- Pseudoprimes to base 60.at n=35A020188
- Pseudoprimes to base 66.at n=40A020194
- Strong pseudoprimes to base 37.at n=12A020263
- Strong pseudoprimes to base 41.at n=15A020267
- Strong pseudoprimes to base 66.at n=11A020292
- Strong pseudoprimes to base 69.at n=16A020295
- Strong pseudoprimes to base 88.at n=14A020314
- Strong pseudoprimes to base 92.at n=29A020318
- a(n) = (2*n+1)*(12*n+1).at n=29A033576
- Riordan array ( (1/(1-x))^m , x*A000108(x) ), m =4.at n=57A185945
- Numbers k such that (19*10^k + 191)/3 is prime.at n=21A280632
- Square array A(n,k), n>=0, k>=0, read by antidiagonals, where A(0,k) = 1 and A(n,k) = Sum_{j=0..n-1} k^j * binomial(n-1,j) * A(j,k) for n > 0.at n=49A306245
- Odd composite integers m such that A014448(m) == 4 (mod m).at n=35A335670
- Odd composite integers m such that U(m)^2 == 1 (mod m) and V(m) == 4 (mod m), where U(m) and V(m) are the m-th generalized Lucas and Pell-Lucas numbers of parameters a=4 and b=-1, respectively.at n=28A337627
- Odd composite integers m such that A000032(3*m-J(m,5)) == 3*J(m,5) (mod m), where J(m,5) is the Jacobi symbol.at n=24A339724
- 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=30A340095
- Odd composite integers m such that A000045(3*m-J(m,5)) == 1 (mod m), where J(m,5) is the Jacobi symbol.at n=28A340235