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.

A076225 Counts of the maximum value in n-th row of A076221.

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%I A076225 #15 May 24 2022 17:17:11
%S A076225 1,2,3,2,3,2,3,3,3,2,3,3,4,3,3,3,4,4,5,5,5,4,5,5,5,4,4,4,5,5,6,6,6,5,
%T A076225 5,5,6,5,5,5,6,6,7,7,7,6,7,7,7,7,7,7,8,8,8,8,8,7,8,8,9,8,8,8,8,8,9,9,
%U A076225 9,9,10,10,11,10,10,10,10,10,11,11,11,10,11,11,11,10,10,10,11,11,11,11,11
%N A076225 Counts of the maximum value in n-th row of A076221.
%C A076225 Does a(n) always equal 1 + pi(n) - pi(n/2), where pi(x) is number of primes <= x? If so a(n) = A056171(n)+1. - _Leroy Quet_, Feb 06 2003.
%C A076225 This is true, because A076221(n,k) = n-1 iff either k = 1 or k is a prime with n/2 < k <= n. - _Robert Israel_, Aug 29 2016
%H A076225 Ethan Berkove and Michael Brilleslyper, <a href="http://math.colgate.edu/~integers/w47/w47.pdf">Subgraphs of Coprime Graphs on Sets of Consecutive Integers</a>, Integers (2022) Vol. 22, #A47, see p. 8.
%p A076225 seq(1+numtheory:-pi(n) - numtheory:-pi(floor(n/2)),n=1..100); # _Robert Israel_, Aug 29 2016
%Y A076225 Cf. A056171, A076221.
%K A076225 nonn
%O A076225 1,2
%A A076225 _Olivier Gérard_