|
Search: id:A097655
|
|
|
| A097655 |
|
Numbers n such that n=d_1!!*d_2!!*...*d_k!! where d_1 d_2 ... d_k is the decimal expansion of n. |
|
+0
7
|
|
| 1, 2, 3, 15, 18432, 75600, 276531978240000, 4810168001497883738112000, 215788176336727572480000000, 2178419737991700039289327133392896000000000000
(list; graph; listen)
|
|
|
OFFSET
|
1,2
|
|
|
COMMENT
|
All terms are of the form 2^i*3^j*5^k*7^l.
|
|
EXAMPLE
|
18432 is in the sequence because 18432=1!!*8!!*4!!*3!!*2!!.
|
|
MATHEMATICA
|
Do[h=IntegerDigits[n]; l=Length[h]; If[n==Product[h[[k]]!!, {k, l}], Print[n]], {n, 2000000000}]
|
|
CROSSREFS
|
Cf. A097653, A097654, A097643, A102279.
Sequence in context: A162108 A162100 A167444 this_sequence A080749 A070973 A054496
Adjacent sequences: A097652 A097653 A097654 this_sequence A097656 A097657 A097658
|
|
KEYWORD
|
base,nonn
|
|
AUTHOR
|
Farideh Firoozbakht (mymontain(AT)yahoo.com), Sep 10 2004
|
|
EXTENSIONS
|
More terms from Farideh Firoozbakht (mymontain(AT)yahoo.com), Jan 08 2005
|
|
|
Search completed in 0.002 seconds
|
