A100817 Product of the digits of n, each doubled.

0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 0, 4, 8, 12, 16, 20, 24, 28, 32, 36, 0, 8, 16, 24, 32, 40, 48, 56, 64, 72, 0, 12, 24, 36, 48, 60, 72, 84, 96, 108, 0, 16, 32, 48, 64, 80, 96, 112, 128, 144, 0, 20, 40, 60, 80, 100, 120, 140, 160, 180, 0, 24, 48, 72, 96, 120, 144, 168

Offset

0,2

Links

Table of n, a(n) for n=0..67.

Formula

a(n) = A007954(n) *2^A055642(n). - R. J. Mathar, Oct 02 2019

Example

10: (1+1)*(0+0)=0

Maple

A100817 := proc(n::integer)
    if n = 0 then
        0;
    else
        mul( 2*d, d=convert(n, base, 10)) ;
    end if;
end proc:
seq(A100817(n), n=0..100) ; # R. J. Mathar, Oct 02 2019

Mathematica

Times@@(2*IntegerDigits[#])&/@Range[0, 70] (* Harvey P. Dale, Jan 16 2012 *)

Prog

(Perl) #!/usr/local/bin/perl -w for $i (1..100){ @j = split "", $i; $prod=1; for (@j){ $prod *= $_ + $_; } print "$prod, "; }

Crossrefs

Cf. A007954.

Sequence in context: A271907 A069816 A088116 * A074157 A076309 A088133

Adjacent sequences: A100814 A100815 A100816 * A100818 A100819 A100820

Keyword

nonn,base,easy

Author

gamo (gamo(AT)telecable.es), Jan 05 2005

Status

approved