A066597 Primes which can be expressed as concatenation of powers of 6 and 0's.

11, 61, 101, 601, 661, 1061, 1361, 1601, 2161, 6011, 6101, 6361, 6661, 10061, 10111, 10601, 11161, 12161, 16001, 16061, 16111, 16361, 16661, 21601, 21611, 21661, 36011, 36061, 36161, 60101, 60161, 60601, 60611, 60661, 61001

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

Sequence in context: A073625 A307628 A106993 * A199326 A078554 A189227

Adjacent sequences: A066594 A066595 A066596 * A066598 A066599 A066600

Keyword

base,easy,nonn,look

Author

Amarnath Murthy, Dec 21 2001

Extensions

Corrected and extended by Christopher Lund (clund(AT)san.rr.com), Apr 14 2002

Status

approved