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 A155551 Triangle read by rows where T(m,n)=2*m*n + m + n - 9. 4
 -5, -2, 3, 1, 8, 15, 4, 13, 22, 31, 7, 18, 29, 40, 51, 10, 23, 36, 49, 62, 75, 13, 28, 43, 58, 73, 88, 103, 16, 33, 50, 67, 84, 101, 118, 135, 19, 38, 57, 76, 95, 114, 133, 152, 171, 22, 43, 64, 85, 106, 127, 148, 169, 190, 211, 25, 48, 71, 94, 117, 140, 163, 186, 209 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS The numbers 2*T(m,n)+19 =(2*n+1)*(2*m+1) are not prime. First column: A016777, second column: A016885, third column: A016993, fourth column: A017209. - Vincenzo Librandi, Nov 20 2012 LINKS Vincenzo Librandi, Rows n = 1..100, flattened EXAMPLE Triangle begins: -5; -2, 3; 1,  8,  15; 4,  13, 22, 31; 7,  18, 29, 40, 51; 10, 23, 36, 49, 62,  75; 13, 28, 43, 58, 73,  88,  103; 16, 33, 50, 67, 84,  101, 118, 135; 19, 38, 57, 76, 95,  114, 133, 152, 171; 22, 43, 64, 85, 106, 127, 148, 169, 190, 211; etc. MATHEMATICA t[n_, k_]:=2 n*k + n + k - 9; Table[t[n, k], {n, 15}, {k, n}]//Flatten (* Vincenzo Librandi, Nov 20 2012 *) PROG (MAGMA) [2*n*k + n + k - 9: k in [1..n], n in [1..11]]; // Vincenzo Librandi, Nov 20 2012 CROSSREFS Cf. A153143, A153144, A016777, A016885, A016993, A017209. Sequence in context: A089261 A111716 A178566 * A259027 A214064 A098584 Adjacent sequences:  A155548 A155549 A155550 * A155552 A155553 A155554 KEYWORD tabl,sign,easy AUTHOR Vincenzo Librandi, Jan 24 2009 STATUS approved

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Last modified December 14 01:22 EST 2019. Contains 329978 sequences. (Running on oeis4.)