login
A097371
Numbers n such that n=(d_1+5)(d_2+5)*...*(d_k+5), where d_1 d_2 ... d_k is the decimal expansion of n.
6
50, 210, 450, 780, 1500, 3920, 16500, 91728, 269500, 493920, 1293600, 266378112, 317447424, 1277337600, 14948388000, 48697248600, 379748636467200
OFFSET
1,1
COMMENTS
All terms are even.
No other terms below 10^100. - Max Alekseyev, Jan 26 2015
EXAMPLE
317447424 is in the sequence because 317447424=(3+5)(1+5)(7+5)(4+5)(4+5)(7+5)(4+5)(2+5)(4+5).
MATHEMATICA
Do[h=IntegerDigits[n]; l=Length[h]; If[n==Product[h[[k]]+5, {k, l}], Print[n]], {n, 800000000}]
CROSSREFS
Sequence in context: A115592 A334808 A273293 * A179755 A186843 A250527
KEYWORD
base,nonn
AUTHOR
Farideh Firoozbakht, Sep 20 2004
EXTENSIONS
4 more terms from Giovanni Resta, Jan 13 2006
STATUS
approved