296099

Properties

Appears in sequences

• Primes that remain prime through 4 iterations of function f(x) = 2x + 1.at n=16A023302
• Initial (unsafe) primes of Cunningham chains of first type with length exactly 5. Primes in A059453 that survive as primes just four "2p+1 iterations", forming chains of exactly 5 terms.at n=10A059764
• Primes of the form 4*k-1 such that 8*k-1, 16*k-1 and 32*k-1 are also primes.at n=30A101795
• Primes of the form 4*k-1 such that 8*k-1, 16*k-1, 32*k-1 and 64*k-1 are also primes.at n=6A101995
• Smallest primes starting a complete four iterations Cunningham chain of the first or second kind.at n=25A110027
• Number of n X 3 0..2 arrays with horizontal differences mod 3 never 1, vertical differences mod 3 never -1, rows lexicographically nondecreasing, and columns lexicographically nonincreasing.at n=18A229423
• Prime numbers for which the sum of reciprocals of nonzero digits equals 1.at n=19A239685
• Consider binary words that begin with 1 such that the subword 00, whenever it appears, is followed by 111. Then a(n) counts such words at length n (including those where the string 111 is yet being completed - see Example).at n=23A340217
• Prime numbersat n=25699