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 A159800 Triangle read by rows in which row n contains a finite triangle as shown below. 5
 1, 1, 2, 2, 2, 3, 2, 1, 2, 2, 1, 1, 2, 2, 3, 3, 3, 3, 4, 4, 3, 3, 4, 5, 4, 3, 2, 3, 4, 4, 3, 2, 1, 2, 3, 3, 3, 2, 1, 1, 2, 2, 3, 3, 3, 4, 4, 4, 4, 4, 5, 5, 5, 4, 4, 5, 6, 6, 5, 4, 4, 5, 6, 7, 6, 5, 4, 3, 4, 5, 6, 6, 5, 4, 3, 2, 3, 4, 5, 5, 5, 4, 3, 2, 1, 2, 3, 4, 4, 4, 4, 3, 2, 1, 1, 2, 2, 3, 3, 3, 4, 4, 4, 4, 5 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 LINKS EXAMPLE The main triangle begins: 1, 1,2,2,2,3,2,1,2,2,1, 1,2,2,3,3,3,3,4,4,3,3,4,5,4,3,2,3,4,4,3,2,1,2,3,3,3,2,1, 1,2,2,3,3,3,4,4,4,4,4,5,5,5,4,4,5,6,6,5,4,4,5,6,7,6,5,4,3,4,5,6,6,5,4,3,... In which row 1 contains a vertex, only: 1 Row 2 contains the triangle: 1 2,2 2,3,2 1,2,2,1 Row 3 contains the triangle: 1 2,2 3,3,3 3,4,4,3 3,4,5,4,3 2,3,4,4,3,2 1,2,3,3,3,2,1 Row 4 contains the triangle: 1 2,2 3,3,3 4,4,4,4 4,5,5,5,4 4,5,6,6,5,4 4,5,6,7,6,5,4 3,4,5,6,6,5,4,3 2,3,4,5,5,5,4,3,2 1,2,3,4,4,4,4,3,2,1 Row 5 contains the triangle: 1 2,2 3,3,3 4,4,4,4 5,5,5,5,5 5,6,6,6,6,5 5,6,7,7,7,6,5 5,6,7,8,8,7,6,5 5,6,7,8,9,8,7,6,5 4,5,6,7,8,8,7,6,5,4 3,4,5,6,7,7,7,6,5,4,3 2,3,4,5,6,6,6,6,5,4,3,2 1,2,3,4,5,5,5,5,5,4,3,2,1 And so on... CROSSREFS Sequence in context: A014843 A116987 A219838 * A273021 A071137 A193990 Adjacent sequences:  A159797 A159798 A159799 * A159801 A159802 A159803 KEYWORD easy,nonn,tabf AUTHOR Omar E. Pol, Nov 09 2009 STATUS approved

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Last modified December 11 04:29 EST 2018. Contains 318049 sequences. (Running on oeis4.)