OFFSET
1,2
EXAMPLE
234 is in the sequence because 2! + 3! + 4! = 32 = 2^5.
MAPLE
with(numtheory):for n from 1 to 2000 do:l:=length(n):n0:=n:s:=0:for m from
1 to l do:q:=n0:u:=irem(q, 10):v:=iquo(q, 10):n0:=v :s:=s+u!:od: q:= evalf(log[2](s));
if floor(q)= q then printf(`%d, `, n):else fi:od:
MATHEMATICA
With[{pwrs2 = 2^Range[0, 200]}, Select[Range[1500], MemberQ[pwrs2, Total[IntegerDigits[#]!]] &]] (* Harvey P. Dale, Jan 03 2011 *)
PROG
(Sage) A174569 = list(n for n in IntegerRange(1, 2000) if sum(factorial(d) for d in n.digits()).is_power_of(2))
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Michel Lagneau, Nov 29 2010
STATUS
approved