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A395154
Sequence generated by the D'Hondt (or Jefferson) apportionment method applied to the "Benford weights" p(k) = log(1+1/k), k >= 1.
2
1, 2, 1, 3, 1, 4, 2, 5, 1, 6, 3, 1, 2, 7, 8, 1, 4, 9, 2, 1, 3, 10, 5, 11, 1, 2, 12, 6, 1, 4, 13, 3, 1, 14, 2, 7, 15, 1, 5, 16, 8, 2, 1, 3, 17, 4, 18, 1, 9, 6, 19, 2, 1, 20, 3, 10, 21, 1, 5, 2, 4, 7, 22, 11, 1, 23, 3, 24, 1, 2, 12, 8, 25, 6, 1, 26, 4, 13, 2, 1
OFFSET
1,2
COMMENTS
The D'Hondt method is applicable even though the sum of the weights is infinite.
a(n) is the number k minimizing (c(k)+1)/p(k), where c(k) is the number of occurrences of k among the previous terms.
No ties occur. Proof: Assume that there is a tie between values j and k at some point. Then log(1+1/j)/log(1+1/k) = (c(j)+1)/(c(k)+1) = r/s is rational, which implies that (j+1)^s/j^s = (k+1)^r/k^r. Both these fractions are in lowest terms (since GCD(j,j+1) = GCD(k,k+1) = 1), so j^s = k^r and (j+1)^s = (k+1)^r, i.e., s*log(j) = r*log(k) and s*log(j+1) = r*log(k+1). This implies that log(j)/log(j+1) = log(k)/log(k+1). Since the function log(x)/log(x+1) is strictly increasing for x > 0, it follows that j = k.
A055440 is the subsequence of terms less than 10. In general, the subsequence of terms less than b is the sequence generated by the D'Hondt method applied to Benford's law for base b.
LINKS
Pontus von Brömssen, Table of n, a(n) for n = 1..10000
Wikipedia, Benford's law.
Wikipedia, D'Hondt method.
FORMULA
Positions of k are given by n_k(m) = Sum_{j>=1} floor(m*log(1+1/j)/log(1+1/k)), m >= 1. (Terms in the series are nonzero only for j <= 1/((1+1/k)^(1/m)-1).)
a(n)*(log n)/n goes to 1/m as n goes to infinity through values such that a(n) occurs for the m-th time, i.e., k*(log n_k(m))/n_k(m) goes to 1/m as k goes to infinity.
CROSSREFS
Cf. A027750 (weights p(k)=1/k), A055440, A084580, A393100, A395001 (weights p(k)=1/sqrt(k)).
Sequence in context: A130747 A370822 A055440 * A250028 A101279 A361735
KEYWORD
nonn
AUTHOR
STATUS
approved