A153144
Numbers n such that 2*n+19 is not a prime.
Original entry on oeis.org
1, 3, 4, 7, 8, 10, 13, 15, 16, 18, 19, 22, 23, 25, 28, 29, 31, 33, 34, 36, 37, 38, 40, 43, 46, 48, 49, 50, 51, 52, 53, 55, 57, 58, 61, 62, 63, 64, 67, 68, 70, 71, 73, 75, 76, 78, 79, 82, 83, 84, 85, 88, 91, 92, 93, 94, 95, 97, 98, 99, 100, 101
Offset: 1
A155550
Triangle read by rows where T(m,n)=2*m*n + m + n - 6.
Original entry on oeis.org
-2, 1, 6, 4, 11, 18, 7, 16, 25, 34, 10, 21, 32, 43, 54, 13, 26, 39, 52, 65, 78, 16, 31, 46, 61, 76, 91, 106, 19, 36, 53, 70, 87, 104, 121, 138, 22, 41, 60, 79, 98, 117, 136, 155, 174, 25, 46, 67, 88, 109, 130, 151, 172, 193, 214, 28, 51, 74, 97, 120, 143, 166, 189, 212
Offset: 1
Triangle begins:
-2;
1, 6;
4, 11, 18;
7, 16, 25, 34;
10, 21, 32, 43, 54;
13, 26, 39, 52, 65, 78;
16, 31, 46, 61, 76, 91, 106;
19, 36, 53, 70, 87, 104, 121, 138;
22, 41, 60, 79, 98, 117, 136, 155, 174;
25, 46, 67, 88, 109, 130, 151, 172, 193, 214; etc.
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[2*n*k + n + k - 6: k in [1..n], n in [1..11]]; // Vincenzo Librandi, Nov 21 2012
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t[n_,k_]:= 2 n*k + n + k - 6; Table[t[n, k], {n, 15}, {k, n}]//Flatten (* Vincenzo Librandi, Nov 21 2012 *)
Showing 1-2 of 2 results.
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