A244948 Least number k > n such that k^32 + n^32 is prime.

30, 29, 40, 33, 34, 131, 50, 9, 44, 11, 38, 13, 18, 97, 166, 221, 200, 37, 82, 61, 176, 23, 102, 65, 94, 151, 352, 87, 38, 37, 38, 39, 46, 37, 48, 137, 54, 55, 68, 43, 60, 55, 146, 51, 106, 87, 82, 65, 134, 53, 106, 103, 90, 71, 96, 71, 148, 91, 94, 139, 74, 69, 94, 75, 86, 169, 100

Offset

1,1

Comments

a(n) = n+1 iff n is in A174156.

Links

Jens Kruse Andersen, Table of n, a(n) for n = 1..10000

Example

34^32 + 35^32 = 35884563485651241417769982593434627193100364196481 is not prime. 34^2 + 36^32 = 2^32*(17^32+18^32) is not prime. 34^32 + 37^32 = 162384303092765940334383766635859112907663593431937 is prime. Thus a(34) = 37.

Prog

(Python)
import sympy
from sympy import isprime
def a(n):
..for k in range(n+1, 10**4):
....if isprime(k**32+n**32):
......return k
n = 1
while n < 100:
..print(a(n), end=', ')
..n += 1
(PARI) a(n)=for(k=n+1, 10^4, if(isprime(k^32+n^32), return(k)))
n=1; while(n<100, print1(a(n), ", "); n++)

Crossrefs

Cf. A158979, A089489, A242555.

Sequence in context: A056998 A057348 A057350 * A282130 A125564 A056997

Adjacent sequences: A244945 A244946 A244947 * A244949 A244950 A244951

Keyword

nonn

Author

Derek Orr, Jul 08 2014

Status

approved