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A109959 Numbers n such that concatenating n and the sum of primes dividing n (counting multiplicity) produces a prime. 2
10, 12, 14, 22, 38, 82, 90, 92, 96, 116, 117, 122, 134, 147, 158, 165, 178, 198, 210, 218, 236, 262, 274, 304, 314, 332, 333, 352, 358, 360, 369, 387, 390, 399, 420, 448, 454, 478, 482, 496, 522, 561, 562, 603, 605, 622, 637, 639, 640, 651, 694, 704, 714, 720 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

7^50+144 generates a 62 digit prime.

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..1000

EXAMPLE

a(5)=38 because 38=2*19 and 19+2=21 and 3821 is prime.

MATHEMATICA

Select[Range[2, 1000], PrimeQ[FromDigits[Join[IntegerDigits[#], IntegerDigits[ Total[Times@@@FactorInteger[#]]]]]]&] (* Harvey P. Dale, Aug 10 2012 *)

CROSSREFS

Cf. A001414, A109958.

Sequence in context: A189555 A116612 A068502 * A161990 A218335 A030591

Adjacent sequences: A109956 A109957 A109958 * A109960 A109961 A109962

KEYWORD

easy,nonn,base

AUTHOR

Jason Earls, Jul 06 2005

STATUS

approved

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Last modified January 29 17:52 EST 2023. Contains 359924 sequences. (Running on oeis4.)