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 A226239 Minimum m such that there exists an n-row subtractive triangle with distinct integers in 1..m. 0
 1, 3, 6, 10, 15, 22, 33, 44, 59, 76, 101, 125 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS In an n-row subtractive triangle, there are n-i+1 integers in the i-th row. The integers in the first row are arbitrary. From the next row, the integers are the absolute difference between adjacent integers in the previous row. LINKS EXAMPLE a(6)=22 because there is a 6-row subtractive triangle with distinct integers in [1..22] as follows: 1:  6 20 22  3 21 13 2: 14  2 19 18  8 3: 12 17  1 10 4:  5 16  9 5: 11  7 6:  4 However, there is no such triangle with distinct integers in [1..21]. CROSSREFS Cf. A035313, A035312. Sequence in context: A122047 A177100 A265071 * A209231 A137358 A143963 Adjacent sequences:  A226236 A226237 A226238 * A226240 A226241 A226242 KEYWORD nonn,hard,more AUTHOR Yi Yang, Jun 01 2013 EXTENSIONS a(12) from Yi Yang, Mar 04 2015 STATUS approved

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Last modified October 18 00:55 EDT 2019. Contains 328135 sequences. (Running on oeis4.)