A173269 - OEIS

A173269

2*prime(prime(n))-3 and 3*prime(prime(n))-2 are both primes.

1, 2, 3, 8, 11, 14, 15, 19, 23, 24, 28, 39, 44, 47, 54, 62, 63, 81, 85, 101, 121, 122, 124, 136, 152, 159, 180, 218, 219, 241, 247, 253, 274, 290, 298, 307, 323, 324, 341, 361, 371, 376, 381, 403, 410, 413, 441, 443, 479, 487, 499, 552, 554, 556, 562, 582, 622

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OFFSET

1,2

LINKS

Table of n, a(n) for n=1..57.

EXAMPLE

a(1)=1 because 2*p(p(1))-3=2*p(2)-3=2*3-3=3=prime and 3*p(p(1))-2=7=prime; a(2)=2 because 2*p(p(2))-3=2*p(3)-3=2*5-3=7=prime and 3*p(p(2))-2=13=prime; a(3)=3 because 2*p(p(3))-3=2*p(5)-3=2*11-3=19=prime and 3*p(p(3))-2=31=prime; a(4)=8 because 2*p(p(8))-3=2*p(19)-3=2*67-3=131=prime and 3*p(p(8))-2=199=prime.

CROSSREFS

Cf. A063908, A088878.

Sequence in context: A084917 A134713 A293910 * A364217 A050557 A039000

Adjacent sequences: A173266 A173267 A173268 * A173270 A173271 A173272

KEYWORD

nonn

AUTHOR

Juri-Stepan Gerasimov, Feb 14 2010

EXTENSIONS

Inserted 23 and 24, removed 34, extended the sequence - R. J. Mathar, Mar 01 2010

STATUS

approved