OFFSET
1,4
COMMENTS
A subsequence of A033308.
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..2000
EXAMPLE
a(1)=1 and a(2)=1 represent the two digits of 11.
a(7)=1 and a(8)=9 represent the two digits of 19.
a(43)=0 and a(44)=0 represent the two zeros of the prime 1009.
MATHEMATICA
cd[n_]:=Module[{idn=IntegerDigits[n], len}, len=IntegerLength[n]/2; Take[ idn, {len, len+1}]]; cd/@Select[Prime[Range[200]], EvenQ[ IntegerLength[ #]]&]//Flatten (* Harvey P. Dale, Jul 23 2018 *)
CROSSREFS
KEYWORD
nonn,base,less
AUTHOR
Juri-Stepan Gerasimov, Jul 21 2009
EXTENSIONS
a(8) corrected by R. J. Mathar, Jul 27 2009
STATUS
approved