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 A297191 Irregular triangle read by rows formed by taking every other row of the Delannoy array (A008288) regarded as a triangle. 3
 1, 1, 3, 1, 1, 7, 13, 7, 1, 1, 11, 41, 63, 41, 11, 1, 1, 15, 85, 231, 321, 231, 85, 15, 1, 1, 19, 145, 575, 1289, 1683, 1289, 575, 145, 19, 1, 1, 23, 221, 1159, 3649, 7183, 8989, 7183, 3649, 1159, 221, 23, 1, 1, 27, 313, 2047, 8361, 22363, 40081, 48639, 40081 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 LINKS Rémy Sigrist, Rows n = 0..100 of triangle, flattened Rémy Sigrist, PARI program for A297191 EXAMPLE The Delannoy triangle begins: ..........1 .........1.1 ........1.3.1 .......1.5.5.1 ......1.7.13.7.1 .....1.9.25.25.9.1 ....1.11.41.63.41.11.1 ...1.13.61.129.129.61.13.1 ..1.15.85.231.321.231.85.15.1 .1.17.113.377.681.681.377.113.17.1 so this triangle begins: ..........1 ........1.3.1 ......1.7.13.7.1 ....1.11.41.63.41.11.1 ..1.15.85.231.321.85.15.1 1.19.145.575.1289.1683.1289.575.145.19.1 ... PROG (PARI) See Links section. CROSSREFS Cf. A008288, A297192. Sequence in context: A112492 A210574 A049290 * A147990 A134567 A131932 Adjacent sequences:  A297188 A297189 A297190 * A297192 A297193 A297194 KEYWORD nonn,tabf,easy AUTHOR N. J. A. Sloane, Jan 10 2018 EXTENSIONS More terms from Rémy Sigrist, Jan 18 2018 STATUS approved

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Last modified June 26 20:03 EDT 2019. Contains 324380 sequences. (Running on oeis4.)