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.

A290636 The arithmetic function v_3(n,4).

This page as a plain text file.
%I A290636 #20 Aug 16 2017 23:43:58
%S A290636 1,0,2,1,3,2,4,2,5,3,6,3,7,3,8,4,9,5,10,6,11,6,12,6,13,6,14,7,15,8,16,
%T A290636 9,17,10,18,9,19,9,20,10,21,11,22,11,23,12,24,14,25,12,26,13,27,15,28,
%U A290636 15,29,15,30,15,31,18,32,16,33,17,34,18,35
%N A290636 The arithmetic function v_3(n,4).
%D A290636 J. Butterworth, Examining the arithmetic function v_g(n,h). Research Papers in Mathematics, B. Bajnok, ed., Gettysburg College, Vol. 8 (2008).
%H A290636 Robert Israel, <a href="/A290636/b290636.txt">Table of n, a(n) for n = 2..10000</a>
%H A290636 Bela Bajnok, <a href="https://arxiv.org/abs/1705.07444">Additive Combinatorics: A Menu of Research Problems</a>, arXiv:1705.07444 [math.NT], May 2017. See Table in Section 1.6.1.
%F A290636 For n >= 3, f(prime(n)) = A024698(n-1). - _Robert Israel_, Aug 16 2017
%p A290636 f:= n -> max(map(t -> (floor((t - 1 - igcd(t, 3))/4) + 1)*n/t, numtheory:-divisors(n))):
%p A290636 map(f, [$2..100]); # _Robert Israel_, Aug 16 2017
%t A290636 v[g_, n_, h_] := (d = Divisors[n]; Max[(Floor[(d - 1 - GCD[d, g])/h] + 1)*n/d]); Table[v[3, n, 4], {n, 2, 70}]
%Y A290636 Cf. A211316 (equals v_1(n,3)).
%Y A290636 Cf. A289435 - A289441.
%Y A290636 Cf. A024698.
%K A290636 nonn
%O A290636 2,3
%A A290636 _Robert Price_, Aug 13 2017