login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A179629 Primes p such that p + the sum of its decimal digits + the sum of the squares of its digits is prime. 1
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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

I suppose that there is an infinite number of 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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 27 06:24 EDT 2019. Contains 323599 sequences. (Running on oeis4.)