A062859 - OEIS

%I #10 Oct 16 2023 23:30:06

%S 1,4,12,18,30,40,60,72,90,120,140,168,180,210,252,280,315,336,360,420,

%T 504,560,630,672,720,792,840,924,990,1008,1155,1232,1260,1320,1386,

%U 1540,1584,1680,1848,1980,2016,2310,2376,2520,2640,2772,2970,3024,3080

%N Size of smallest triangular multiplication table which contains some number n times.

%e a(4)=18 because the size-18 triangular multiplication table is the smallest to contain a particular number 4 times (namely the number A062858(4)=36).

%o (Python)

%o from itertools import count

%o from collections import Counter

%o def A062859(n):

%o     c = Counter()

%o     for m in count(1):

%o         for i in range(1,m+1):

%o             ij = i*m

%o             c[ij] += 1

%o             if c[ij]>=n:

%o                 return m # _Chai Wah Wu_, Oct 16 2023

%Y The least such number is A062858(n).

%Y Cf. A027424, A062851, A062854, A062855, A062856, A062857, A062858, A000217.

%K nonn

%O 1,2

%A Ron A. Lalonde (ronronronlalonde(AT)hotmail.com), Jun 25 2001

%E More terms from _Don Reble_, Nov 08 2001