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A175120 a(1)=2. a(n) = the smallest prime p > a(n-1) such that p-a(n-1)-1 is composite. 3
2, 7, 17, 43, 53, 79, 89, 139, 149, 199, 227, 263, 313, 347, 373, 383, 409, 419, 541, 557, 593, 619, 641, 677, 727, 743, 769, 797, 823, 839, 983, 1009, 1019, 1069, 1091, 1117, 1151, 1187, 1213, 1223, 1249, 1259, 1381, 1409, 1459, 1481, 1531, 1553, 1579, 1601 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
A175121(n) = A175120(n+1) - A175120(n) - 1.
LINKS
MATHEMATICA
sp[n_]:=Module[{np=NextPrime[n], pa1}, pa1=np-n-1; While[PrimeQ[pa1] || pa1==1, np=NextPrime[np]; pa1=np-n-1]; np]; Join[{2}, NestList[sp, 7, 50]] (* Harvey P. Dale, Jan 10 2012 *)
CROSSREFS
Sequence in context: A365069 A347079 A370304 * A239357 A106910 A108479
KEYWORD
nonn
AUTHOR
Leroy Quet, Feb 14 2010
EXTENSIONS
Extended by R. J. Mathar, Feb 21 2010
STATUS
approved

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Last modified March 1 13:16 EST 2024. Contains 370433 sequences. (Running on oeis4.)