cp's OEIS Frontend

A177862 Irregular triangle read by rows in which row n (n>=0) is a list of the numbers of different regions into which n lines can divide the plane.

%I A177862 #26 Aug 01 2020 01:20:43
%S A177862 1,2,3,4,4,6,7,5,8,9,10,11,6,10,12,13,14,15,16,7,12,15,16,17,18,19,20,
%T A177862 21,22
%N A177862 Irregular triangle read by rows in which row n (n>=0) is a list of the numbers of different regions into which n lines can divide the plane.
%H A177862 O. A. Ivanov, <a href="http://www.jstor.org/stable/10.4169/000298910x523362">On the number of regions into which n straight lines divide the plane</a>, Amer. Math. Monthly, 117 (2010), 881-888.
%e A177862 Triangle begins:
%e A177862   1
%e A177862   2
%e A177862   3  4
%e A177862   4  6  7
%e A177862   5  8  9 10 11
%e A177862   6 10 12 13 14 15 16
%e A177862   7 12 15 16 17 18 19 20 21 22
%e A177862   ...
%Y A177862 A000124, A055503, and A263883 are subsequences.
%Y A177862 Cf. A241600.
%K A177862 nonn,tabf,more
%O A177862 0,2
%A A177862 _N. J. A. Sloane_, Dec 18 2010
%E A177862 Duplicate term 22 removed on row n=6 and example fixed by _Luc Rousseau_, Feb 25 2019