A173577 7-Factorions: equal to the sum of the 7-fold factorials of their digits in base 10.

1, 2, 3, 4, 5, 6, 7, 8, 19

Offset

1,2

Links

Table of n, a(n) for n=1..9.

Example

19 -> 1!!!!!!! + 9!!!!!!! = 1 + 9*2 = 1 + 18 = 19.

Maple

P:=proc(n, m) local a, b, i, j, k, x, w; for i from 1 by 1 to n do a:=0; b:=0; w:=0; k:=i; while k>0 do w:=k-(trunc(k/10)*10); j:=w; x:=w-m; if w=0 then b:=1; else while x>0 do j:=j*x; x:=x-m; od; b:=j; fi; a:=a+b; k:=trunc(k/10); od; if a=i then lprint(i, a); fi; od; end: P(1000, 7);

Crossrefs

A014080, A097653, A173573-A173576

Sequence in context: A260354 A114799 A055557 * A103205 A363490 A039127

Adjacent sequences: A173574 A173575 A173576 * A173578 A173579 A173580

Keyword

easy,fini,full,nonn,base

Author

Paolo P. Lava and Giorgio Balzarotti, Feb 22 2010

Extensions

Definition corrected by Paolo P. Lava, Feb 24 2010

Status

approved