OFFSET
1,1
COMMENTS
Note that the first 18 multiples of 11 have even digital sums.
Indices of odd entries in A136614. - R. J. Mathar, Nov 23 2010
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
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..]
-- Reinhard Zumkeller, Jul 05 2014
CROSSREFS
KEYWORD
nonn,base
AUTHOR
David Radcliffe, Nov 23 2010
STATUS
approved