A179629 Primes p such that p + the sum of its decimal digits + the sum of the squares of its digits is prime.

23, 59, 83, 89, 127, 181, 229, 233, 239, 241, 257, 283, 293, 359, 383, 389, 421, 457, 523, 541, 547, 557, 563, 571, 577, 599, 659, 683, 751, 787, 809, 811, 829, 839, 853, 859, 877, 883, 887, 1021, 1087, 1129, 1151, 1181, 1187, 1217, 1223, 1249, 1279, 1289

Offset

1,1

Comments

I suppose that there are infinitely many twin primes in the sequence, e.g., (239,241), (809,811), (1877,1879).

Links

Table of n, a(n) for n=1..50.

Example

a(3)=83 since 83+(8+3)+(8^2+3^2) = 83+11+73 = 167 is a prime.

Prog

(PARI) isok(n) = {if (isprime(n), digs = digits(n, 10); isprime(n + sum(i=1, #digs, digs[i]) + sum(i=1, #digs, digs[i]^2)); , 0; ); } \\ Michel Marcus, Jul 18 2013

Crossrefs

Sequence in context: A043949 A005111 A225550 * A274381 A044125 A044506

Adjacent sequences: A179626 A179627 A179628 * A179630 A179631 A179632

Keyword

nonn,base

Author

Carmine Suriano, Jul 21 2010

Status

approved