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A216658
Number of n-digit 8th powers.
2
2, 0, 1, 1, 1, 1, 2, 2, 4, 4, 6, 8, 11, 14, 18, 25, 34, 44, 60, 79, 105, 141, 187, 250, 334, 445, 593, 791, 1054, 1407, 1875, 2501, 3336, 4447, 5931, 7909, 10547, 14065, 18755, 25010, 33353, 44475, 59310, 79090, 105469, 140645, 187553, 250105, 333522, 444758
OFFSET
1,1
LINKS
EXAMPLE
a(1) = 2: 0, 1.
a(3) = 1: 256.
a(4) = 1: 6561.
a(9) = 4: 100000000, 214358881, 429981696, 815730721.
a(10) = 4: 1475789056, 2562890625, 4294967296, 6975757441.
a(11) = 6: 11019960576, 16983563041, 25600000000, 37822859361, 54875873536, 78310985281.
MAPLE
r:= proc(n, k) local b; b:= iroot(n, k); b+`if`(b^k<n, 1, 0) end:
a:= n-> r(10^n, 8) -r(10^(n-1), 8) +`if`(n=1, 1, 0):
seq(a(n), n=1..60);
MATHEMATICA
Join[{2, 0}, Tally[IntegerLength[Range[2, 18*10^5]^8]][[;; , 2]]] (* Harvey P. Dale, Sep 15 2024 *)
CROSSREFS
Column k=8 of A216653.
Sequence in context: A369258 A337930 A340691 * A214020 A029425 A219055
KEYWORD
nonn,base
AUTHOR
Alois P. Heinz, Sep 12 2012
STATUS
approved