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A261371 Prime numbers that sum to a prime when added to their digital root. 0
11, 13, 29, 53, 67, 71, 89, 101, 103, 137, 191, 193, 227, 229, 233, 269, 281, 359, 431, 449, 461, 463, 499, 569, 593, 641, 643, 659, 683, 701, 719, 769, 821, 823, 857, 859, 877, 967, 1019, 1061, 1091, 1093, 1223, 1289, 1439, 1451, 1487, 1489, 1579, 1597, 1601, 1619 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..52.

FORMULA

(a(n) mod 9) mod 2 = 0. - Altug Alkan, Sep 28 2015

EXAMPLE

11 (prime) + 2 (its digital root) = 13 (prime);

89 (prime) + 8 (its digital root) = 97 (prime).

MATHEMATICA

Select[Prime[Range[300]], PrimeQ[# + Mod[#, 9]] &] (* Vincenzo Librandi, Sep 29 2015 *)

PROG

(PARI) lista(nn) = forprime(p=2, nn, if (isprime(p + p%9), print1(p, ", "))); \\ Michel Marcus, Sep 12 2015

(MAGMA) [p: p in PrimesUpTo(2000) | IsPrime(p+(p mod 9))]; // Vincenzo Librandi, Sep 29 2015

CROSSREFS

Cf. A000040, A010888, A038194.

Sequence in context: A158759 A107645 A106014 * A289490 A056251 A222805

Adjacent sequences:  A261368 A261369 A261370 * A261372 A261373 A261374

KEYWORD

nonn,base

AUTHOR

Gary Croft, Sep 11 2015

STATUS

approved

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Last modified September 22 22:42 EDT 2018. Contains 315270 sequences. (Running on oeis4.)