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A210062
Number of digits in 7^n.
6
1, 1, 2, 3, 4, 5, 6, 6, 7, 8, 9, 10, 11, 11, 12, 13, 14, 15, 16, 17, 17, 18, 19, 20, 21, 22, 22, 23, 24, 25, 26, 27, 28, 28, 29, 30, 31, 32, 33, 33, 34, 35, 36, 37, 38, 39, 39, 40, 41, 42, 43, 44, 44, 45, 46, 47, 48, 49, 50, 50, 51, 52, 53, 54, 55, 55, 56, 57
OFFSET
0,3
LINKS
FORMULA
a(n) = A055642(A000420(n)) = A055642(7^n) = floor(log_10(10*(7^n))). [Jonathan Vos Post, Mar 23 2012]
MATHEMATICA
Table[Length[IntegerDigits[7^n]], {n, 0, 100}] (* T. D. Noe, Mar 20 2012 *)
PROG
(Magma) [#Intseq(7^n): n in [0..67]]; // Bruno Berselli, Mar 22 2012
CROSSREFS
Number of digits in b^n: A034887 (b=2), A034888 (b=3), A210434 (b=4), A210435 (b=5), A210436 (b=6), this sequence (b=7).
Sequence in context: A238839 A269169 A248148 * A245337 A006164 A053758
KEYWORD
nonn,base,easy
AUTHOR
Luc Comeau-Montasse, Mar 16 2012
STATUS
approved