

A054684


Sum of digits is odd.


11



1, 3, 5, 7, 9, 10, 12, 14, 16, 18, 21, 23, 25, 27, 29, 30, 32, 34, 36, 38, 41, 43, 45, 47, 49, 50, 52, 54, 56, 58, 61, 63, 65, 67, 69, 70, 72, 74, 76, 78, 81, 83, 85, 87, 89, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 111, 113, 115, 117, 119, 120, 122, 124, 126, 128, 131
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OFFSET

1,2


COMMENTS

Union of A179083 and A179085; A179081(a(n)) = 1.  Reinhard Zumkeller, Jun 28 2010


LINKS

R. Zumkeller, Table of n, a(n) for n = 1..1000
Index entries for 10automatic sequences.
Index entries for Colombian or self numbers and related sequences


FORMULA

a(n) = n * 2  1 for the first 5 numbers; a(n) = n * 2 for the second 5 numbers.
From Robert Israel, Jun 27 2017: (Start)
a(n) = 2*n2 if floor((n1)/5) is in the sequence, 2*n1 if not.
G.f. g(x) satisfies g(x) = (1x)*(1+x+x^2+x^3+x^4)^2*g(x^10)/x^9 + x^2*(2+x^4+3*x^5x^9+3*x^10)/((1x)*(1+x^5))^2.
(End)


EXAMPLE

1, 3, 5, 7, 9, 10(1), 12(3), 14(5), 16(7), 18(9), 21(3) and so on.


MAPLE

[seq(`if`(convert(convert(2*n1, base, 10), `+`)::odd, 2*n1, 2*n2), n=1..501)];


PROG

(PARI) is(n)=my(d=digits(n)); sum(i=1, #d, d[i])%2 \\ Charles R Greathouse IV, Aug 09 2013


CROSSREFS

Cf. A054683.
Sequence in context: A287774 A308412 A327254 * A294601 A080207 A187347
Adjacent sequences: A054681 A054682 A054683 * A054685 A054686 A054687


KEYWORD

nonn,easy,base


AUTHOR

Odimar Fabeny, Apr 19 2000


EXTENSIONS

More terms from James A. Sellers, Apr 19 2000


STATUS

approved



