A291358 The arithmetic function u(n,2,4).

5, 2, 3, 2, 5, 2, 5, 2, 3, 2, 5, 2, 5, 2, 3, 2, 5, 2, 5, 2, 3, 2, 5, 2, 5, 2, 3, 2, 5, 2, 5, 2, 3, 2, 5, 2, 5, 2, 3, 2, 5, 2, 5, 2, 3, 2, 5, 2, 5, 2, 3, 2, 5, 2, 5, 2, 3, 2, 5, 2, 5, 2, 3, 2, 5, 2, 5, 2, 3, 2, 5, 2, 5, 2, 3, 2, 5, 2, 5, 2, 3, 2, 5, 2, 5, 2, 3, 2, 5, 2, 5, 2, 3, 2, 5, 2, 5, 2, 3, 2, 5, 2, 5, 2, 3

Offset: 1

Author

Robert Price, Aug 23 2017

Keywords

• nonn

Links

• Antti Karttunen, Table of n, a(n) for n = 1..65537
• Bela Bajnok, Additive Combinatorics: A Menu of Research Problems, arXiv:1705.07444 [math.NT], May 2017. See Table in Section 1.6.3.

Crossrefs

Cf. A289435, A289436, A289437, A289438, A289439, A289440, A289441.

Programs

Mathematica

u[n_, m_, h_] := (d = Divisors[n]; Min[(h*Ceiling[m/d] - h + 1)*d]); Table[u[n, 2, 4], {n, 1, 70}]

PARI

A291358(n, m=2, h=4) = { my(p=0,k); fordiv(n,d,k = d*(h*ceil(m/d) - h + 1); if(!p || (k < p), p = k)); (p); }; \\ Antti Karttunen, Oct 01 2018

Extensions

More terms from Antti Karttunen, Oct 01 2018