A131100 - OEIS

%I #13 Dec 05 2020 11:24:57

%S 1,1,4,1,2,3,1,2,4,5,1,2,3,5,6,1,2,3,4,5,7,1,2,3,4,5,6,7,1,2,3,4,5,6,

%T 8,10,1,2,3,4,5,6,7,8,13,1,2,3,4,5,6,8,9,10,11,1,2,3,4,5,6,7,8,9,10,

%U 11,1,2,3,4,5,6,7,8,9,10,11,13

%N Indices of A002808 such that A081545(m) = Product_{k=m*(m-1)/2+1..m*(m+1)/2} A002808(a(k)).

%H Jinyuan Wang, <a href="/A131100/b131100.txt">Rows n = 1..100 of triangle, flattened</a>

%e a(2..3) = {1,4} since A081545(2) = A002808(1)*A002808(4) + 1;

%e a(7..10) = {1,2,4,5} since A081545(4) = A002808(1)*A002808(2)*A002808(4)*A002808(5) + 1.

%e Triangle begins:

%e 1;

%e 1, 4;

%e 1, 2, 3;

%e 1, 2, 4, 5;

%e 1, 2, 3, 5, 6;

%e 1, 2, 3, 4, 5, 7;

%e 1, 2, 3, 4, 5, 6, 7;

%e ...

%Y Cf. A002808, A081545.

%K nonn,tabl

%O 1,3

%A _M. F. Hasler_, Jun 14 2007

%E Offset changed to 1 by and more terms from _Jinyuan Wang_, Dec 04 2020