OFFSET
1,1
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
EXAMPLE
1361 is a term as it is a concatenation of 1, 36 and 1 which are powers of 6.
MAPLE
P[1]:= {1}: R:= NULL:
for d from 2 to 6 do
P[d]:= P[d-1]:
for i from 0 do
q:= 6^i; dq:= ilog10(q)+1;
if dq >= d then break fi;
qq:= 10^(d-dq)*q;
C:= map(t -> t + qq, P[d-dq]);
R:= R, op(select(isprime, C));
P[d]:= P[d] union C;
od
od:
A:= sort([R]); # Robert Israel, Jul 31 2020
CROSSREFS
KEYWORD
AUTHOR
Amarnath Murthy, Dec 21 2001
EXTENSIONS
Corrected and extended by Christopher Lund (clund(AT)san.rr.com), Apr 14 2002
STATUS
approved