cp's OEIS Frontend

A332377 One-third of total number of edges in graph formed by the straight line segments connecting the edges of an equilateral triangle with the n-1 points resulting from a subdivision of the sides into n equal pieces.

%I A332377 #17 Feb 14 2020 03:22:03
%S A332377 1,4,13,18,41,48,85,94,145,156,221,234,313,328,415,438,545,564,685,
%T A332377 700,841,864,1013,1014,1201,1228,1405,1434,1625,1650,1861,1894,2113,
%U A332377 2148,2369,2418,2665,2704,2965,2988,3281,3312,3613,3658,3919,4008,4325
%N A332377 One-third of total number of edges in graph formed by the straight line segments connecting the edges of an equilateral triangle with the n-1 points resulting from a subdivision of the sides into n equal pieces.
%H A332377 N. J. A. Sloane, <a href="/A332377/b332377.txt">Table of n, a(n) for n = 1..1000</a>
%F A332377 a(n) = (A092098(n) + A331782(n) - 1)/3 = A332376(n)/3.
%Y A332377 Cf. A091908, A092098 (number of cells), A331782 (number of vertices), A332376.
%K A332377 nonn
%O A332377 1,2
%A A332377 _N. J. A. Sloane_, Feb 13 2020