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A061825
Multiples of 7 containing only odd digits.
2
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
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
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