t3x.org / sketchy / library / oddp.html
SketchyLISP
Reference
  Copyright (C) 2007
Nils M Holm

odd?

Conformance: R5RS Scheme

Purpose: Test whether a number is odd (not even).

Arguments:
X - number

Model:

(define (odd? x)
  (not (even? x)))

Implementation:

(define (odd? x)
  (and (memq (car (reverse (integer->list x)))
             (integer->list 13579))
       #t))

Example:

(odd? 3) 
=> #t

See also:
digits, even?, zero?.