A097371 - OEIS

%I #10 Jan 26 2015 15:02:00

%S 50,210,450,780,1500,3920,16500,91728,269500,493920,1293600,266378112,

%T 317447424,1277337600,14948388000,48697248600,379748636467200

%N 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.

%C All terms are even.

%C No other terms below 10^100. - _Max Alekseyev_, Jan 26 2015

%e 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).

%t Do[h=IntegerDigits[n];l=Length[h];If[n==Product[h[[k]]+5, {k, l}], Print[n]], {n, 800000000}]

%Y Cf. A097372, A098681.

%K base,nonn

%O 1,1

%A _Farideh Firoozbakht_, Sep 20 2004

%E 4 more terms from _Giovanni Resta_, Jan 13 2006