A061825 Multiples of 7 containing only odd digits.

7, 35, 77, 91, 119, 133, 175, 315, 357, 371, 399, 511, 539, 553, 595, 735, 777, 791, 917, 931, 959, 973, 1113, 1155, 1197, 1337, 1351, 1379, 1393, 1519, 1533, 1575, 1715, 1757, 1771, 1799, 1911, 1939, 1953, 1995, 3115, 3157, 3171, 3199, 3311, 3339

Offset

1,1

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Index entries for 10-automatic sequences.

Example

315 = 7*45 is a term as it contains only odd digits.

Maple

R:= NULL:
for d from 1 to 4 do
  for n from 5^d to 2*5^d-1 do
    L:= map(t -> 2*t+1, convert(n, base, 5)[1..d]);
    x:= add(L[i]*10^(i-1), i=1..nops(L));
    if x mod 7 = 0 then
      R:= R, x;
    fi;
od od:
R; # Robert Israel, Nov 02 2019

Mathematica

Select[7*Range[500], Count[IntegerDigits[#], _?EvenQ]==0&] (* Harvey P. Dale, Jun 13 2011 *)

Prog

(PARI) is(n)=n%7==0 && #setintersect(Set(digits(n)), [0, 2, 4, 6, 8])==0 \\ Charles R Greathouse IV, Feb 15 2017

Crossrefs

Subsequence of A008589.

Cf. A061826.

Sequence in context: A247158 A285802 A340523 * A077536 A256391 A152744

Adjacent sequences: A061822 A061823 A061824 * A061826 A061827 A061828

Keyword

nonn,base,easy

Author

Amarnath Murthy, May 28 2001

Extensions

More terms from Larry Reeves (larryr(AT)acm.org), May 30 2001

Status

approved