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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.
1
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
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
KEYWORD
easy,nonn
AUTHOR
Paolo P. Lava and Giorgio Balzarotti, Mar 07 2007, Mar 08 2007
STATUS
approved