OFFSET
1,1
LINKS
Daniel Starodubtsev, Table of n, a(n) for n = 1..10000
EXAMPLE
At k=10, k1111 = 101111 (prime).
At k=90, k1111 = 901111 (prime).
At k=138, k1111 = 1381111 (prime).
MATHEMATICA
Select[ Range[ 350], PrimeQ[ FromDigits[ Flatten[ IntegerDigits /@ { #, 1, 1, 1, 1}]]] &] (* Robert G. Wilson v, Feb 21 2005 *)
Select[Range[400], PrimeQ[#*10^4+1111]&] (* Harvey P. Dale, Jul 14 2019 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Parthasarathy Nambi, Feb 18 2005
EXTENSIONS
More terms from Robert G. Wilson v, Feb 21 2005
STATUS
approved