cp's OEIS Frontend

A340791 Irregular triangle read by rows in which row n lists the positive divisors of n that are >= sqrt(n) in decreasing order.

%I A340791 #34 Jan 30 2021 11:35:24
%S A340791 1,2,3,4,2,5,6,3,7,8,4,9,3,10,5,11,12,6,4,13,14,7,15,5,16,8,4,17,18,9,
%T A340791 6,19,20,10,5,21,7,22,11,23,24,12,8,6,25,5,26,13,27,9,28,14,7,29,30,
%U A340791 15,10,6,31,32,16,8,33,11,34,17,35,7,36,18,12,9,6,37,38,19
%N A340791 Irregular triangle read by rows in which row n lists the positive divisors of n that are >= sqrt(n) in decreasing order.
%C A340791 Reversing rows gives A161908.
%e A340791 Triangle begins:
%e A340791    1
%e A340791    2
%e A340791    3
%e A340791    4  2
%e A340791    5
%e A340791    6  3
%e A340791    7
%e A340791    8  4
%e A340791    9  3
%e A340791   10  5
%e A340791   11
%e A340791   12  6  4
%e A340791   13
%e A340791   14  7
%e A340791   15  5
%e A340791   16  8  4
%e A340791   17
%e A340791   18  9  6
%e A340791   19
%e A340791   20 10  5
%e A340791   21  7
%e A340791   22 11
%e A340791   23
%e A340791   24 12  8  6
%o A340791 (PARI) row(n) = Vecrev(select(x->(x>=sqrt(n)), divisors(n))); \\ _Michel Marcus_, Jan 22 2021
%Y A340791 Cf. A038548 (row widths), A160180 (second column), A161908 (rows reversed), A340792.
%K A340791 nonn,tabf
%O A340791 1,2
%A A340791 _Charles Kusniec_, Jan 21 2021