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A178330
Numbers n such that d(1)^1 + d(2)^2 +... + d(p)^p is a power of 2, where d(i), i=1..p, are the decimal digits of n.
0
1, 2, 4, 8, 10, 11, 20, 31, 40, 42, 71, 75, 80, 100, 101, 110, 123, 200, 211, 215, 301, 305, 310, 321, 400, 413, 420, 503, 611, 651, 701, 710, 750, 800, 842, 1000, 1001, 1010, 1100, 1111, 1151, 1230, 2000, 2011, 2051, 2101, 2110, 2150, 2211, 3001, 3010, 3050, 3100, 3131, 3201, 3210, 3623, 3694, 4000, 4031, 4130, 4200, 4222, 4433
OFFSET
1,2
EXAMPLE
7496 is in the sequence because 7 + 4^2 + 9^3 + 6^4 = 2048 = 2^11.
MAPLE
with(numtheory):for n from 1 to 10000 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^(l-m+1):od: x:=evalf(log[2](s)):if
x=floor(x) then printf(`%d, `, n):else fi:od:
CROSSREFS
Sequence in context: A265155 A070305 A174567 * A029992 A346139 A206928
KEYWORD
nonn,base
AUTHOR
Michel Lagneau, Dec 21 2010
STATUS
approved