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A174569 Numbers n such that sum of factorials of digits of n is a power of 2. 1
1, 2, 10, 11, 22, 23, 32, 102, 103, 112, 113, 120, 121, 130, 131, 200, 201, 210, 211, 234, 235, 243, 253, 300, 301, 310, 311, 324, 325, 342, 352, 423, 432, 523, 532, 1000, 1001, 1010, 1011, 1034, 1035, 1043, 1053, 1100, 1101, 1110, 1111, 1134, 1135, 1143, 1153, 1304, 1305, 1314, 1315, 1340 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..56.

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

Sequence in context: A051373 A131096 A069263 * A179884 A174570 A072545

Adjacent sequences:  A174566 A174567 A174568 * A174570 A174571 A174572

KEYWORD

nonn,base

AUTHOR

Michel Lagneau, Nov 29 2010

STATUS

approved

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Last modified October 20 16:07 EDT 2021. Contains 348111 sequences. (Running on oeis4.)