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A298638 Numbers k such that the digital sum of k and the digital root of k have opposite parity. 3
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, 91, 92, 93, 94, 95, 96, 97, 98, 99, 109, 118, 119, 127, 128, 129, 136, 137, 138, 139, 145, 146, 147, 148, 149, 154, 155 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Numbers k such that A113217(k) <> A179081(k).
Complement of A298639.
Agrees with A291884 until a(46): a(46) = 109 is not in that sequence.
LINKS
MATHEMATICA
Select[Range[145], EvenQ@ Total@ IntegerDigits@ # != EvenQ@ NestWhile[Total@ IntegerDigits@ # &, #, # > 9 &] &] (* Michael De Vlieger, Feb 03 2018 *)
PROG
(Python)
#Digital sum of n.
def ds(n):
if n < 10:
return n
return n % 10 + ds(n//10)
def A298638(term_count):
seq = []
m = 0
n = 1
while n <= term_count:
s = ds(m)
r = ((m - 1) % 9) + 1 if m else 0
if s % 2 != r % 2:
seq.append(m)
n += 1
m += 1
return seq
print(A298638(100))
(PARI) isok(n) = sumdigits(n) % 2 != if (n, ((n-1)%9+1) % 2, 0); \\ Michel Marcus, Mar 01 2018
CROSSREFS
Sequence in context: A069529 A138335 A304367 * A291884 A173639 A091448
KEYWORD
nonn,easy,base
AUTHOR
J. Stauduhar, Jan 23 2018
STATUS
approved

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Last modified April 21 10:39 EDT 2024. Contains 371852 sequences. (Running on oeis4.)