28549

Properties

Appears in sequences

• Primes of the form p^k - p + 1 for prime p.at n=20A034915
• Primes p such that p and p^2 have same digit sum.at n=36A058370
• Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 0), (-1, -1, 1), (-1, 0, 0), (0, -1, 0), (1, 1, 0)}.at n=9A149503
• Triangle T(n, k) = T(n-1, k) + T(n-1, k-1) + ((n+1)*(n+2)/2)*T(n-2, k-1), read by rows.at n=31A154227
• Triangle T(n, k) = T(n-1, k) + T(n-1, k-1) + ((n+1)*(n+2)/2)*T(n-2, k-1), read by rows.at n=32A154227
• Primes p such that p-2 and q are primes, where q is concatenation of binary representations of p and p-2: q = p * 2^L + p-2, where L is the length of binary representation of p-2: L=A070939(p-2).at n=41A232237
• Number of length-4 0..n arrays with no adjacent pair x,x+1 repeated.at n=12A269657
• Primes p such that 2*p + 23 is a square.at n=37A269785
• Twin primes both of which are the sum of three positive cubes.at n=23A272376
• Primes that can be generated by the concatenation in base 3, in ascending order, of two consecutive integers read in base 10.at n=36A287300
• Numbers b > 1 such that the smallest four primes, i.e., 2, 3, 5 and 7 are base-b Wieferich primes.at n=32A339533
• Primes p such that 2*p-1 and (2*p-1)^2+(2*p)^2 are also prime.at n=33A347165
• a(n) is the greatest prime p such that p + q^2 + r^3 = prime(n)^4 for some primes q and r.at n=4A361930
• a(n) = Sum_{1 <= x_1, x_2, x_3 <= n} n/gcd(x_1, x_2, x_3, n).at n=12A372952
• Prime numbersat n=3106