A163672 - OEIS

%I #15 Sep 08 2022 08:45:46

%S 11,14,19,17,24,31,20,29,38,47,23,34,45,56,67,26,39,52,65,78,91,29,44,

%T 59,74,89,104,119,32,49,66,83,100,117,134,151,35,54,73,92,111,130,149,

%U 168,187,38,59,80,101,122,143,164,185,206,227,41,64,87,110,133,156,179

%N Triangle T(n,m) = 2mn + m + n + 7 read by rows.

%C 2*T(n,n) - 13 = (2n+1)^2.

%C The numbers 2*T(m,n)-13 =(2*n+1)*(2*m+1) are not prime. Also: first column: A016789; second column: A016897; third column: A017017; fourth column: A017185. - _Vincenzo Librandi_, Nov 20 2012

%H Vincenzo Librandi, <a href="/A163672/b163672.txt">Rows n = 1..100, flattened</a>

%F T(n,m) = A163674(n,m)-2 = A163657(n,m)-1.

%e Triangle begins:

%e   11;

%e   14,  19;

%e   17,  24,  31;

%e   20,  29,  38,  47;

%e   23,  34,  45,  56,  67;

%e   26,  39,  52,  65,  78,  91;

%e   29,  44,  59,  74,  89, 104, 119;

%e   32,  49,  66,  83, 100, 117, 134, 151;

%t t[n_,k_]:=2 n*k + n + k + 7; Table[t[n, k], {n, 15}, {k, n}]//Flatten (* _Vincenzo Librandi_, Nov 20 2012 *)

%o (Magma) [2*n*k + n + k + 7: k in [1..n], n in [1..11]]; // _Vincenzo Librandi_, Nov 20 2012

%o (PARI) for(n=1,10, for(m=1,n, print1(2*m*n + m + n + 7, ", "))) \\ _G. C. Greubel_, Aug 02 2017

%Y Cf. A016789, A016897, A017017, A017185, A153049, A163674, A163657.

%K nonn,easy,tabl

%O 1,1

%A _Vincenzo Librandi_, Aug 03 2009

%E Edited by _R. J. Mathar_, Oct 12 2009