A171566 Primes p such that 2*p-3 and 2*(2*p-3)-3 are primes (First member of a primes in a 2*p-3 double progression).
3, 5, 7, 13, 17, 23, 37, 43, 97, 107, 113, 127, 157, 167, 223, 283, 317, 373, 433, 547, 563, 587, 617, 647, 743, 757, 773, 937, 1123, 1277, 1297, 1423, 1483, 1487, 1543, 1583, 1597, 1667, 1697, 1823, 1913, 1933, 1973, 2137, 2143, 2243, 2333, 2437, 2467
Offset: 1
Keywords
Examples
2*3-3=3, 2*5-3=7; 2*7-3=11, 2*7-3=11; 2*11-3=19,..
References
- Mohammad K. Azarian, Double Progression, Problem 231, Math Horizons, Vol. 16, Issue 4, April 2009, p. 31. Solution published in Vol. 17, Issue 2, November 2009, p. 32.
Links
- Harvey P. Dale, Table of n, a(n) for n = 1..1000
Crossrefs
Cf. A063908
Programs
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Mathematica
Select[Prime[Range[7! ]],PrimeQ[2*#-3]&&PrimeQ[2*(2*#-3)-3]&] Select[Prime[Range[400]],AllTrue[{2#-3,4#-9},PrimeQ]&] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Jul 04 2021 *)