OFFSET
1,1
COMMENTS
As n increases, a(n)/(n*(log(P(n))^2)) is always near 1.200.
LINKS
Pierre CAMI, Table of n, a(n) for n = 1..10000
EXAMPLE
6*3*2^2-1=71 , 71 and 73 twin primes so a(1)=3 as prime(1)=2.
6*5*3^2-1=269 269 and 271 twin primes so a(2)=5 as prime(2)=3.
PROG
PFGW64 from Primeform group and Scriptify
Command : PFGW64 -f in.txt
in.txt file :
SCRIPT
DIM nn, 0
DIM kk, 0
DIMS tt
OPENFILEOUT myfile, values.txt
LABEL loopn
SET nn, nn+1
IF nn>50000 THEN END
LABEL loopk
SET kk, kk+1
SETS tt, %d, %d\ ; nn; kk
PRP 6*kk*p(nn)^2-1, tt
IF ISPRP THEN GOTO a
IF ISPRIME THEN GOTO a
GOTO loopk
LABEL a
PRP 6*kk*p(nn)^2+1, tt
IF ISPRP THEN GOTO b
IF ISPRIME THEN GOTO b
GOTO loopk
LABEL b
WRITE myfile, tt
GOTO loopn
CROSSREFS
KEYWORD
nonn
AUTHOR
Pierre CAMI, Feb 18 2012
STATUS
approved