cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A237288 Lexicographically earliest sequence of noncomposite numbers such that a(n)*n / sum(i=1..n, a(n) ) is strictly increasing.

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%I A237288 #9 Apr 23 2025 18:10:16
%S A237288 1,2,3,5,7,11,17,23,31,41,53,67,83,101,127,151,179,211,251,293,337,
%T A237288 389,443,503,569,641,719,809,907,1009,1117,1229,1361,1493,1637,1787,
%U A237288 1949,2129,2309,2503,2707,2917,3137,3371,3613,3877,4153,4441,4751,5059,5381
%N A237288 Lexicographically earliest sequence of noncomposite numbers such that a(n)*n / sum(i=1..n, a(n) ) is strictly increasing.
%C A237288 If we replace in name of sequence:
%C A237288 noncomposite numbers -> nonprime numbers, then a(n) = A103517(n-1),
%C A237288 noncomposite numbers -> composite numbers, then a(n) = A103517(n),
%C A237288 noncomposite numbers -> primes, then a(n) = A237285(n),
%C A237288 noncomposite numbers -> natural numbers, then a(n) = A000027(n).
%e A237288 For n=8: noncomposite number a(8) = 23 > a(7) = 17 is the smallest noncomposite number such that (8*23 / 69) > (7*17 / 46), a(8) is not 19 because (8*19 / (69-4)) < (7*17 / 46).
%Y A237288 Cf. A008578 (noncomposite numbers).
%K A237288 nonn
%O A237288 1,2
%A A237288 _Jaroslav Krizek_, Feb 28 2014