OFFSET
0,3
COMMENTS
Rd(abcd) = abcd*bcd*cd*d, etc.
LINKS
Reinhard Zumkeller, Table of n, a(n) for n = 0..10000
FORMULA
a(n) = Product_{k=1..length(n)} (n-10^k*floor(n/10^k)). - Vladeta Jovovic, Jan 08 2002
a(n) = 0 iff n == 0 (mod 10). - M. F. Hasler, Feb 25 2019
EXAMPLE
Rd(256) = 256*56*6 = 86016.
MATHEMATICA
Table[d = IntegerDigits[n]; rd = 1; While[ Length[d] > 0, rd = rd*FromDigits[d]; d = Drop[d, 1]]; rd, {n, 1, 75} ]
Join[{0}, Table[Times@@FromDigits/@NestList[Rest[#]&, IntegerDigits[n], IntegerLength[ n]-1], {n, 70}]] (* Harvey P. Dale, Nov 29 2014 *)
PROG
(Haskell)
import Data.List (tails)
a067079 = product . map read . init . tails . show :: Integer -> Integer
-- Reinhard Zumkeller, Apr 23 2013
(PARI) A067079(n)=prod(k=1, logint(n+!n, 10)+1, n-n\10^k*10^k) \\ M. F. Hasler, Feb 25 2019
CROSSREFS
KEYWORD
AUTHOR
Amarnath Murthy, Jan 05 2002
EXTENSIONS
More terms from Robert G. Wilson v, Jan 07 2002
STATUS
approved