A007959 Some nontrivial permutation of digits is an odd number.

10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103

Offset

1,1

Comments

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

Links

Robert Israel, Table of n, a(n) for n = 1..10000

F. Smarandache, Only Problems, Not Solutions!

Formula

a(n) ~ n. - Charles R Greathouse IV, Sep 19 2012

Example

The transposition (1,2) (nontrivial permutation of order two) acting on 11 yields the odd number 11. - M. F. Hasler, Sep 30 2012

Maple

filter:= proc(n) local L;
  L:= convert(n, base, 10) mod 2;
  (L[1]=1 and nops(L) > 2) or max(L[2..-1])=1
end proc:
select(filter, [$10..1000]); # Robert Israel, Nov 21 2016

Prog

(PARI) is_A007959(n)=bittest(n, 0)&n>99 || while(n\=10, bittest(n, 0) & return(1)) \\ M. F. Hasler, Sep 30 2012

Crossrefs

Cf. A007930.

Sequence in context: A070839 A161561 A307560 * A102492 A169905 A076161

Adjacent sequences: A007956 A007957 A007958 * A007960 A007961 A007962

Keyword

nonn,base

Author

R. Muller

Status

approved