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A216655
Number of n-digit 5th powers.
2
2, 1, 1, 3, 3, 6, 10, 14, 24, 36, 59, 93, 147, 232, 369, 585, 927, 1470, 2328, 3690, 5849, 9270, 14692, 23285, 36904, 58490, 92699, 146919, 232850, 369042, 584894, 926993, 1469185, 2328502, 3690426, 5848932, 9269933, 14691853, 23285017, 36904265, 58489320
OFFSET
1,1
LINKS
EXAMPLE
a(1) = 2: 0, 1.
a(2) = 1: 32.
a(3) = 1: 243.
a(4) = 3: 1024, 3125, 7776.
a(5) = 3: 16807, 32768, 59049.
a(6) = 6: 100000, 161051, 248832, 371293, 537824, 759375.
a(7) = 10: 1048576, 1419857, 1889568, 2476099, 3200000, 4084101, 5153632, 6436343, 7962624, 9765625.
MAPLE
r:= proc(n, k) local b; b:= iroot(n, k); b+`if`(b^k<n, 1, 0) end:
a:= n-> r(10^n, 5) -r(10^(n-1), 5) +`if`(n=1, 1, 0):
seq(a(n), n=1..50);
CROSSREFS
Column k=5 of A216653.
Sequence in context: A184834 A276777 A219876 * A242884 A197219 A300508
KEYWORD
nonn,base
AUTHOR
Alois P. Heinz, Sep 12 2012
STATUS
approved