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A096787
Primes of form 4n+3 that are the sum of two consecutive composite numbers.
13
19, 31, 43, 67, 71, 79, 103, 127, 131, 139, 151, 163, 191, 199, 211, 223, 239, 251, 271, 283, 307, 311, 331, 367, 379, 419, 431, 439, 443, 463, 487, 491, 499, 523, 547, 571, 599, 607, 619, 631, 643, 647, 659, 683, 691, 727, 739, 743, 751, 787, 811, 823, 827
OFFSET
1,1
LINKS
FORMULA
Equals 1+2*A096788.
MATHEMATICA
2Select[ Range[ 450], PrimeQ[ # ] == PrimeQ[ # + 1] == False && PrimeQ[2# + 1, GaussianIntegers -> True] == True &] + 1 (* Robert G. Wilson v, Jul 11 2004 *)
Select[Total/@Partition[Select[Range[500], CompositeQ], 2, 1], PrimeQ[#] && IntegerQ[ (#-3)/4]&] (* Harvey P. Dale, Mar 06 2019 *)
PROG
(PARI) nextcomposite(k)=if(k<3, 4, if(isprime(k), k+1, k));
{m=440; n=4; while(n<m, k=nextcomposite(n+1); p=n+k; if(isprime(p)&&(p%4)==3, print1(p, ", ")); n=k)} \\ Klaus Brockhaus, Jul 10 2004
CROSSREFS
Subsequence of A060254. See A096788 for values 2n+1. See A096676 for n values.
Sequence in context: A043298 A286313 A040068 * A104006 A117065 A006035
KEYWORD
nonn
AUTHOR
Lekraj Beedassy, Jul 09 2004
EXTENSIONS
Corrected and extended by Klaus Brockhaus and Ray Chandler, Jul 10 2004
STATUS
approved