OFFSET
1,2
COMMENTS
The j values are either 7 and 8 for k=1. For larger k, there is one j only: 8, 7, 7, 8, 5, 5, 1, 5, 8, 4, 5, 4, 2, 8, 8, 4, 7, 1, 7, 4, 7, 5, 1, 7, 8, 1, 7, 7, 1, 4, 7, 7, 4, 5, 8, 8, 1, 5, 1, 1, 4, 7, 1, 7, 2.
The next k is probably near 160000 to 200000
LINKS
EXAMPLE
10^3-7*10^1-1=929 prime as 10^3-8*10^1-1=919 so a(1)=1.
PROG
(PFGW)
' PFGW64 and SCRIPTIFY from Primeform Group
' Command : pfgw64 -f in.txt
' in.txt file :
SCRIPT
DIM nn, 0
DIM kk
DIMS tt
OPENFILEOUT myfile, a(n).txt
LABEL loopn
SET nn, nn+1
IF nn>200000 THEN END
SET kk, 0
LABEL loopk
SET kk, kk+1
IF kk%3==0 THEN SET kk, kk+1
IF kk>8 THEN GOTO loopn
SETS tt, %d, %d\,; nn; kk
PRP (10^(nn+1)-kk)*10^nn-1, tt
IF ISPRIME THEN GOTO a
IF ISPRP THEN GOTO a
GOTO loopk
LABEL a
WRITE myfile, tt
GOTO loopk
' Results in a(n)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Pierre CAMI, Jun 23 2012
STATUS
approved