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A321568 Least prime p such that p plus the sum of its digits is the n-th prime after p. 2
11, 19, 37, 59, 97, 55787, 26699, 663959, 6974477, 86966771, 1095975857, 4649574977, 349685387573, 988839709939, 86396869388567 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The other way round is not feasible because p minus the sum of its digits is never a prime but a multiple of 9.

LINKS

Table of n, a(n) for n=1..15.

Carlos Rivera, Puzzle 935. pi+SOD(pi)=p(i+n), The Prime Puzzles and Problems Connection.

EXAMPLE

a(1) = 11 because 11 + 1 + 1 = 13 that is the first prime after 11.

a(2) = 19 because 19 + 1 + 9 = 29 that is the second prime after 19.

MAPLE

P:=proc(q) local a, b, c, d, n, x; x:=0; d:=[]; for n from 1 to q do

x:=nextprime(x); a:=x+convert(convert(x, base, 10), `+`);

if isprime(a) then c:=0; b:=x; while b<a do b:=nextprime(b); c:=c+1; od;

if numboccur(c, d)=0 then d:=[op(d), c]; lprint(c, x, a); fi; fi;

od; end: P(10^13); # Terms not in order.

MATHEMATICA

Array[Block[{p = 2}, While[p + Total@ IntegerDigits@ p != NextPrime[p, #], p = NextPrime@ p]; p] &, 8] (* Michael De Vlieger, Dec 17 2018 *)

CROSSREFS

Cf. A000040, A007953, A321569, A321570.

Sequence in context: A052368 A226542 A117873 * A271779 A271840 A076853

Adjacent sequences:  A321565 A321566 A321567 * A321569 A321570 A321571

KEYWORD

base,nonn,more

AUTHOR

Paolo P. Lava, Dec 17 2018

EXTENSIONS

a(12)-a(15) from Giovanni Resta, Dec 17 2018

STATUS

approved

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Last modified June 6 01:51 EDT 2020. Contains 334858 sequences. (Running on oeis4.)