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A252005 a(1)=2; for n>1, a(n) is the least prime > a(n-1) such that sum of digits of a(n-1) and a(n) is prime. 2
2, 3, 11, 23, 53, 83, 101, 113, 149, 179, 239, 269, 293, 311, 347, 359, 383, 401, 419, 449, 479, 557, 563, 593, 617, 647, 653, 683, 743, 773, 839, 863, 929, 953, 983, 1019, 1061, 1091, 1151, 1163, 1223, 1301, 1319, 1367, 1373, 1439, 1481, 1493, 1553, 1583, 1607, 1619, 1667, 1697, 1733, 1787, 1823 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Zak Seidov, Table of n, a(n) for n = 1..1000

EXAMPLE

a(2)=3, next primes are 5, 7, 11 and only 3+1+1 is prime, hence

a(3)=11, next primes are 13, 17, 19, 23 and only 1+1+2+3 is prime, hence a(4)=23, etc.

MATHEMATICA

lp[n_]:=Module[{p=NextPrime[n], tid=Total[IntegerDigits[n]]}, While[ CompositeQ[ Total[ IntegerDigits[p]]+tid], p=NextPrime[p]]; p]; NestList[ lp, 2, 60] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Sep 30 2018 *)

CROSSREFS

Cf. A007953, A252006.

Sequence in context: A263729 A246496 A119641 * A074496 A292817 A292112

Adjacent sequences:  A252002 A252003 A252004 * A252006 A252007 A252008

KEYWORD

base,nonn

AUTHOR

Zak Seidov, Dec 12 2014

STATUS

approved

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Last modified July 2 18:27 EDT 2022. Contains 355029 sequences. (Running on oeis4.)