t3x.org / sketchy / library / oddp.html
SketchyLISP
Reference
  Copyright (C) 2006
Nils M Holm

odd?

Conformance: R5RS

Purpose: Test a number n for being odd (n modulo 2 = 1).

Arguments:
X - number

Model:

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

Implementation:

(define (odd? x)
  (neq? (memq (car (reverse (integer->list x)))
              (integer->list 13579))
        #f))

Example:

(odd? 3) 
=> #t

See also:
digits, even?, zero?.