A089718 a(0) = 1, a(n) = number obtained by multiplying each digit of a(n-1) by n. May be called digitfactorial of n.

1, 1, 2, 6, 24, 1020, 60120, 4207140, 32160568320, 2718954045547227180, 207010809050400405050407020207010800, 22077011088099055044004405505504407702202207701108800, 24240848401212096960108108060600484800484806060060600484808484024240242408484012120969600

Offset: 0

Author

Amarnath Murthy, Nov 18 2003

Keywords

• base
• easy
• nonn

Links

• Alois P. Heinz, Table of n, a(n) for n = 0..15

Crossrefs

Cf. A000142, A110728.

Programs

Maple

str10:=proc(n) if n<>0 then RETURN(convert(n,base,10)) else RETURN([0]) fi end:ds:=proc(s) local j: RETURN(add(s[j]*10^(j-1),j=1..nops(s))): end: ap:=1: for n from 1 to 12 do m:=ds([seq(op(str10(i*n)),i=str10(ap))]): printf("%d, ",m):ap:=m od: # C. Ronaldo
# second Maple program:
a:= proc(n) option remember; `if`(n=0, 1, (l-> parse(cat(seq(
       l[-i]*n, i=1..nops(l)))))(convert(a(n-1), base, 10)))
    end:
seq(a(n), n=0..12);  # Alois P. Heinz, Dec 12 2020

Mathematica

nxt[{n_,a_}]:={n+1,FromDigits[Flatten[IntegerDigits/@((n+1)*IntegerDigits[ a])]]}; Transpose[NestList[nxt,{1,1},10]][[2]] (* Harvey P. Dale, Mar 26 2015 *)

Extensions

More terms from C. Ronaldo (aga_new_ac(AT)hotmail.com), Dec 25 2004

a(0)=1 prepended by Alois P. Heinz, Dec 12 2020