A227191 a(n) = n minus (product of nonzero digits in factorial base representation of n).

0, 1, 2, 2, 3, 5, 6, 7, 8, 8, 9, 10, 11, 12, 13, 12, 13, 15, 16, 17, 18, 16, 17, 23, 24, 25, 26, 26, 27, 29, 30, 31, 32, 32, 33, 34, 35, 36, 37, 36, 37, 39, 40, 41, 42, 40, 41, 46, 47, 48, 49, 48, 49, 52, 53, 54, 55, 54, 55, 56, 57, 58, 59, 56, 57, 60, 61, 62

Offset: 1

Author

Antti Karttunen, Jul 04 2013

Keywords

• nonn
• base

Examples

			22 has factorial expansion A007623(22) = "320", and multiplying the nonzero digits, we get 3*2 = 6, and 22-6 = 16, thus a(22)=16.
		

Links

• Antti Karttunen, Table of n, a(n) for n = 1..5040
• Index entries for sequences related to factorial base representation.

Crossrefs

Cf. A007623, A227153, A219651, A227190.

Programs

Mathematica

a[n_] := Module[{k = n, m = 2, r, p = 1}, While[{k, r} = QuotientRemainder[k, m]; k != 0|| r != 0, If[r > 0, p *= r]; m++]; n - p]; Array[a, 100] (* Amiram Eldar, Feb 14 2024 *)

Scheme

(define (A227191 n) (- n (A227153 n)))

Formula

a(n) = n - A227153(n).