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A078403 Primes such that digital root (A038194) is prime. 10
2, 3, 5, 7, 11, 23, 29, 41, 43, 47, 59, 61, 79, 83, 97, 101, 113, 131, 137, 149, 151, 167, 173, 191, 223, 227, 239, 241, 257, 263, 277, 281, 293, 311, 313, 317, 331, 347, 349, 353, 367, 383, 389, 401, 419, 421, 439, 443, 457, 461, 479, 491, 509, 547, 563, 569 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..56.

EXAMPLE

59 is a term because 5+9=14, giving (final) iterated sum 1+4=5 and 5 is prime.

MATHEMATICA

Select[ Range[580], PrimeQ[ # ] && PrimeQ[Mod[ #, 9]] &]

Select[Prime[Range[200]], PrimeQ[Mod[#, 9]]&] (* Harvey P. Dale, Aug 20 2017 *)

PROG

(PARI) forprime(p=2, 997, if(isprime(p%9), print1(p, ", ")))

CROSSREFS

Cf. A070027, A078400.

Sequence in context: A284146 A317479 A087521 * A129945 A046704 A089392

Adjacent sequences:  A078400 A078401 A078402 * A078404 A078405 A078406

KEYWORD

base,easy,nonn

AUTHOR

N. J. A. Sloane, Dec 26 2002

EXTENSIONS

Extended by Robert G. Wilson v, Klaus Brockhaus and Rick L. Shepherd, Dec 27 2002

STATUS

approved

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Last modified August 24 23:01 EDT 2019. Contains 326314 sequences. (Running on oeis4.)