A022923 Number of integers m such that 7^n < 2^m < 7^(n+1).
2, 3, 3, 3, 3, 2, 3, 3, 3, 3, 2, 3, 3, 3, 3, 2, 3, 3, 3, 3, 2, 3, 3, 3, 3, 2, 3, 3, 3, 3, 3, 2, 3, 3, 3, 3, 2, 3, 3, 3, 3, 2, 3, 3, 3, 3, 2, 3, 3, 3, 3, 2, 3, 3, 3, 3, 3, 2, 3, 3, 3, 3, 2, 3, 3, 3, 3, 2, 3, 3, 3, 3, 2, 3, 3, 3, 3, 2, 3, 3, 3, 3, 3, 2, 3, 3, 3, 3, 2, 3, 3, 3, 3, 2, 3, 3, 3, 3, 2
Offset: 0
Examples
From _Amiram Eldar_, Mar 01 2024: (Start) a(0) = 2 because 7^0 = 1 < 2^1 = 2 < 2^2 = 4 < 7^1 = 7. a(1) = 3 because 7^1 = 7 < 2^3 = 8 < 2^4 = 16 < 2^3 = 32 < 7^2 = 49. a(2) = 3 because 7^2 = 49 < 2^6 = 64 < 2^7 = 128 < 2^8 = 256 < 7^3 = 343. (End)
Links
- Harvey P. Dale, Table of n, a(n) for n = 0..1000
Programs
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Mathematica
Differences[Floor[Log2[7^Range[0,100]]]] (* Harvey P. Dale, Jun 23 2019 *)
Formula
Asymptotic mean: lim_{m->oo} (1/m) * Sum_{k=1..m} a(k) = log_2(7) (A020860). - Amiram Eldar, Mar 01 2024