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A078403
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Primes such that digital root (A038194) is prime.
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9
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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; internal format)
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OFFSET
| 1,1
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EXAMPLE
| 59 is a term because 5+9=14, giving (final) iterated sum 1+4=5 and 5 is prime.
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MATHEMATICA
| Select[ Range[580], PrimeQ[ # ] && PrimeQ[Mod[ #, 9]] &]
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PROG
| (PARI) forprime(p=2, 997, if(isprime(p%9), print1(p, ", ")))
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CROSSREFS
| Cf. A070027, A078400.
Sequence in context: A048278 A068863 A087521 * A129945 A046704 A089392
Adjacent sequences: A078400 A078401 A078402 * A078404 A078405 A078406
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KEYWORD
| base,easy,nonn
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com), Dec 26 2002
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EXTENSIONS
| Extended by Robert G. Wilson v (rgwv(AT)rgwv.com), Klaus Brockhaus (klaus-brockhaus(AT)t-online.de) and Rick L. Shepherd (rshepherd2(AT)hotmail.com), Dec 27 2002
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