20051

Properties

Appears in sequences

• Primes that remain prime through 3 iterations of function f(x) = 9x + 4.at n=38A023297
• Consider a room of size r X s where rs = 2n and 1 <= r <= s; count ways to arrange n Tatami mats in room; a(n) = total number of ways for all choices of r and s. Two arrangements are considered the same if one is a rotation or reflection of the other.at n=27A052270
• Luhn primes: primes p such that p + (p reversed) is also a prime.at n=30A061783
• Sum of terms in n-th rows of triangle in A077159.at n=34A077162
• a(n) is the n-th prime whose decimal expansion begins with the decimal expansion of n.at n=19A077345
• Row sums of A081964.at n=34A081966
• Primes congruent to 50 mod 59.at n=36A142777
• Primes congruent to 43 mod 61.at n=35A142841
• G.f.: A(x) = exp( Sum_{n>=1} x^n/(1 - 2^(n^2)*x^n)/n ).at n=8A161637
• a(n) is a prime number that cannot be the center term of a length 3 arithmetic progression prime group with a common difference whose number of runs in binary expansion is 2.at n=26A231387
• Primes which become cubes when the digits are rotated once to the left.at n=5A234929
• Indices of squares of primes in A098550.at n=35A251240
• Primes of the form 7*k^2 + 7*k + 17.at n=41A256374
• Primes of the form abs(3n^3 - 183n^2 + 3318n - 18757) in order of increasing nonnegative n.at n=42A272401
• Prime values in A067439, in the order in which they appear.at n=35A340736
• Primes which, when added to their reversals, produce palindromic primes.at n=7A342681
• Primes having only {0, 1, 2, 5} as digits.at n=42A386018
• Prime numbersat n=2268