|
|
A173639
|
|
Numbers n such that the sum of the digits of 11*n is odd.
|
|
1
|
|
|
19, 28, 29, 37, 38, 39, 46, 47, 48, 49, 55, 56, 57, 58, 59, 64, 65, 66, 67, 68, 69, 73, 74, 75, 76, 77, 78, 79, 82, 83, 84, 85, 86, 87, 88, 89, 119, 128, 129, 137, 138, 139, 146, 147, 148, 149
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
COMMENTS
|
Note that the first 18 multiples of 11 have even digital sums.
|
|
LINKS
|
|
|
EXAMPLE
|
19 is on the list because 11*19 = 209 and 2+0+9 is odd.
|
|
MAPLE
|
L := []; for n to 150 do if `mod`(add(i, i = convert(11*n, base, 10)), 2) = 1 then L := [op(L), n] end if end do; L;
|
|
MATHEMATICA
|
Select[Range[200], OddQ[Total[IntegerDigits[11#]]]&] (* Harvey P. Dale, May 28 2012 *)
|
|
PROG
|
(Python)
ans = []
for n in range(1, 151):
N, s = 11*n, 0
while N:
s += N % 10
N //= 10
if s % 2:
ans.append(n)
print(ans)
(Haskell)
a173639 n = a173639_list !! (n-1)
a173639_list = filter (odd . a007953 . (* 11)) [0..]
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,base
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|