cp's OEIS Frontend

A162609 Triangle read by rows in which row n lists n terms, starting with 1, with gaps = n-2 between successive terms.

%I A162609 #15 Jul 25 2023 13:11:42
%S A162609 1,1,1,1,2,3,1,3,5,7,1,4,7,10,13,1,5,9,13,17,21,1,6,11,16,21,26,31,1,
%T A162609 7,13,19,25,31,37,43,1,8,15,22,29,36,43,50,57,1,9,17,25,33,41,49,57,
%U A162609 65,73,1,10,19,28,37,46,55,64,73,82,91,1,11,21,31,41,51,61,71,81
%N A162609 Triangle read by rows in which row n lists n terms, starting with 1, with gaps = n-2 between successive terms.
%C A162609 Equals A081493 when first column is removed. - _Georg Fischer_, Jul 25 2023
%F A162609 T(n,n) = A002061(n-1).
%F A162609 T(n,k) = A076110(n-1,k) = 1+(n-2)*(k-1). - _R. J. Mathar_, Mar 30 2023
%e A162609 Triangle begins:
%e A162609   1;
%e A162609   1,  1;
%e A162609   1,  2,  3;
%e A162609   1,  3,  5,  7;
%e A162609   1,  4,  7, 10, 13;
%e A162609   1,  5,  9, 13, 17, 21;
%e A162609   1,  6, 11, 16, 21, 26, 31;
%t A162609 Table[NestList[#+(n-2)&,1,n-1],{n,20}]//Flatten (* _Harvey P. Dale_, Oct 23 2017 *)
%Y A162609 Cf. A002061, A159797, A159798, A162610, A161611, A162612, A162613.
%Y A162609 Cf. A060354 (row sums), A081493 (without first column).
%K A162609 easy,nonn,tabl
%O A162609 1,5
%A A162609 _Omar E. Pol_, Jul 09 2009