A178332 Numbers n such that d(1)^p + d(2)^p-1 +... + d(p)^1 is a power of 2, where d(i), i=1..p, are the digits of n.

1, 2, 4, 8, 10, 11, 13, 17, 20, 24, 57, 100, 101, 103, 107, 110, 112, 116, 123, 156, 200, 248, 305, 314, 321, 480, 503, 512, 1000, 1001, 1003, 1007, 1010, 1012, 1016, 1023, 1056, 1100, 1102, 1106, 1111, 1115, 1122, 1155, 1247, 1304, 1313, 1320, 1502, 1511, 2037, 2040, 2136, 2208, 2217, 2224, 2394, 3263, 3344

Offset

1,2

Links

Table of n, a(n) for n=1..59.

Example

2394 is in the sequence because 2^4 + 3^3 + 9^2 + 4^1 = 128 = 2^7.

Maple

with(numtheory):for n from 1 to 4000 do:l:=length(n):n0:=n:s1:=0:s2:=0:for
  m from 1 to l do:q:=n0:u:=irem(q, 10):v:=iquo(q, 10):n0:=v :s2:=s2+u^m:od:x:=evalf(log[2](s2)):if  x=floor(x) then printf(`%d, `, n):else fi:od:

Crossrefs

Sequence in context: A296691 A028836 A028838 * A265155 A070305 A174567

Adjacent sequences: A178329 A178330 A178331 * A178333 A178334 A178335

Keyword

nonn,base

Author

Michel Lagneau, Dec 21 2010

Status

approved