cp's OEIS Frontend

A007959 Some nontrivial permutation of digits is an odd number.

%I A007959 #17 Nov 21 2016 04:18:39
%S A007959 10,11,12,13,14,15,16,17,18,19,30,31,32,33,34,35,36,37,38,39,50,51,52,
%T A007959 53,54,55,56,57,58,59,70,71,72,73,74,75,76,77,78,79,90,91,92,93,94,95,
%U A007959 96,97,98,99,100,101,102,103
%N A007959 Some nontrivial permutation of digits is an odd number.
%C A007959 Also: Odd numbers with more than 2 digits (so you can swap any two digits other than the last one), or numbers having at least one odd digit not in the last position (so you can swap that one with the last digit). - _M. F. Hasler_, Sep 30 2012
%H A007959 Robert Israel, <a href="/A007959/b007959.txt">Table of n, a(n) for n = 1..10000</a>
%H A007959 F. Smarandache, <a href="http://www.gallup.unm.edu/~smarandache/OPNS.pdf">Only Problems, Not Solutions!</a>
%F A007959 a(n) ~ n. - _Charles R Greathouse IV_, Sep 19 2012
%e A007959 The transposition (1,2) (nontrivial permutation of order two) acting on 11 yields the odd number 11. - _M. F. Hasler_, Sep 30 2012
%p A007959 filter:= proc(n) local L;
%p A007959   L:= convert(n,base,10) mod 2;
%p A007959   (L[1]=1 and nops(L) > 2) or max(L[2..-1])=1
%p A007959 end proc:
%p A007959 select(filter, [$10..1000]); # _Robert Israel_, Nov 21 2016
%o A007959 (PARI) is_A007959(n)=bittest(n,0)&n>99 || while(n\=10, bittest(n,0) & return(1)) \\ _M. F. Hasler_, Sep 30 2012
%Y A007959 Cf. A007930.
%K A007959 nonn,base
%O A007959 1,1
%A A007959 R. Muller