A126145 Starting from P0=3, the sequence list the minimum prime P1>P0 for which the expression P=P1+P0-1 is also a prime. The search then restarts from P1.

3, 5, 7, 11, 13, 17, 31, 37, 43, 47, 61, 67, 71, 79, 89, 103, 109, 131, 139, 173, 181, 193, 197, 223, 227, 241, 251, 271, 277, 281, 283, 311, 331, 347, 373, 379, 383, 439, 443, 487, 491, 523, 541, 547, 557, 607, 617, 643, 647, 661, 701, 709, 719, 733, 739, 743

Offset

0,1

Links

Harvey P. Dale, Table of n, a(n) for n = 0..1000

Example

3+5-1=7 is a prime. 5 is in the sequence.
5+7-1=11 is a prime: 11 is in the sequence.
11+13-1=23 is a prime: 13 is in the sequence.
13+17-1=29 is a prime: 17 is in the sequence.
17+19-1=35 is not a prime.

Maple

P:=proc(n) local i, w; w:=3; for i from 3 by 1 to n do if isprime(w+ithprime(i)-1) then print(ithprime(i)); w:=ithprime(i); fi; od; end: P(500);

Mathematica

nxt[n_]:=NestWhile[NextPrime[#]&, NextPrime[n], !PrimeQ[n+#-1]&]; NestList[ nxt, 3, 60] (* Harvey P. Dale, Oct 02 2011 *)

Crossrefs

Sequence in context: A032529 A154866 A106284 * A206864 A155801 A228118

Adjacent sequences: A126142 A126143 A126144 * A126146 A126147 A126148

Keyword

easy,nonn

Author

Paolo P. Lava and Giorgio Balzarotti, Mar 07 2007, Mar 08 2007

Status

approved