42422

Appears in sequences

• All 81 combinations of prefixing and following a(n) by a single digit are nonprime.at n=32A032734
• Composite numbers k such that all the decimal concatenations ik and ikj (i, j = 1...9) are also composite.at n=22A032737
• Numbers k such that 2^k + 3^k is a semiprime.at n=33A050244
• Numbers k such that (2^k + 3^k)/13 is prime.at n=15A181628
• Semiprimes sp such that sp plus its digit sum is a perfect square.at n=34A244733
• Number of (n+1)X(3+1) 0..3 arrays with nondecreasing x(i,j)+x(i,j-1) in the i direction and nondecreasing absolute value of x(i,j)-x(i-1,j) in the j direction.at n=1A250671
• T(n,k)=Number of (n+1)X(k+1) 0..3 arrays with nondecreasing x(i,j)+x(i,j-1) in the i direction and nondecreasing absolute value of x(i,j)-x(i-1,j) in the j direction.at n=7A250676
• Number of (2+1)X(n+1) 0..3 arrays with nondecreasing x(i,j)+x(i,j-1) in the i direction and nondecreasing absolute value of x(i,j)-x(i-1,j) in the j direction.at n=2A250678
• Numbers k such that 363*2^k+1 is prime.at n=28A323006
• Numbers whose prime factorization (prime factors and exponents) contains the digits 1 and 2 at least once, but no other digits.at n=31A364484