This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A179081 Parity of sum of digits of n. 10
 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 COMMENTS a(n) = A000035(A007953(n)); characteristic function of numbers with an odd sum of digits in their decimal representation: a(A054684(n)) = 1; a(A054683(n)) = 0; a(A179083(n)) = a(A179085(n)) = 1; a(A179082(n)) = a(A179084(n)) = 0. LINKS R. Zumkeller, Table of n, a(n) for n = 0..10000 FORMULA a(n) = if n<10 then (n mod 2) else a([n/10]) XOR (n mod 2). EXAMPLE a(789) = (7+8+9) mod 2 = 0; a(790) = (7+9+0) mod 2 = 0; a(791) = (7+9+1) mod 2 = 1. MATHEMATICA Array[Mod[Total[IntegerDigits[#]], 2]&, 110, 0] (* Harvey P. Dale, Feb 20 2013 *) PROG (PARI) a(n) = vecsum(digits(n)) % 2 \\ Jeppe Stig Nielsen, Jan 06 2018 CROSSREFS Sequence in context: A327532 A073445 A285589 * A113217 A189219 A189008 Adjacent sequences:  A179078 A179079 A179080 * A179082 A179083 A179084 KEYWORD base,nonn AUTHOR Reinhard Zumkeller, Jun 28 2010 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified October 17 12:49 EDT 2019. Contains 328112 sequences. (Running on oeis4.)