A097654 Numbers n such that n=|d_1!!-d_2!!+...+(-1)^(k-1)*d_k!!| where d_1 d_2 ... d_k is the decimal expansion of n.

1, 2, 3, 380

Offset: 1

Author

Farideh Firoozbakht, Sep 10 2004

Keywords

• base
• fini
• full
• nonn

Examples

			380 is in the sequence because 380=|3!!-8!!+0!!|.
		

Crossrefs

Cf. A097653, A097655, A097643.

Programs

Mathematica

Do[h=IntegerDigits[n];l=Length[h];If[n==Abs[Sum[(-1)^(k-1) *h[[k]]!!, {k, l}]], Print[n]], {n, 4*9!!}]