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 A137682 Left border of triangle A137680. 5
 1, 1, 3, 7, 17, 40, 96, 228, 544, 1296, 3089, 7361, 17544, 41810, 99643, 237471, 565946, 1348773, 3214424, 7660679, 18257085, 43510652, 103695461, 247129108, 588963062, 1403628615, 3345155947, 7972242937, 18999609718, 45280252031 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS Each term in the sequence (n>1) = sum of previous terms of triangle A137680 = partial sums of sequence A137681: (1, 2, 4, 10, 23,...). Starting (1, 3, 7,...) = INVERT transform of A160096 [Gary W. Adamson, May 01 2009] LINKS FORMULA Partial sums of sequence A137681 prefaced with a 1. a(n) = sum of all terms in rows 1 through (n-1) in triangle A137680. EXAMPLE First few rows of triangle A137680 = 1; 1, 1; 3, 0, 1; 7, 2, 0, 1; ... a(5) = 17 = sum of 1 through 4 row terms of triangle A137680: (1 + 2 + 4 + 10); where (1, 2, 4, 10, 23,...) = A137681 = row sums of triangle A137680 = first difference row of A137682, n>1. MAPLE A137682 := proc(n)     A137680(n, 1) ; end proc: seq(A137682(n), n=1..30) ; # R. J. Mathar, Aug 12 2012 CROSSREFS Cf. A137680, A137681. Cf. A160096. Sequence in context: A309538 A036885 A247300 * A190360 A167213 A249753 Adjacent sequences:  A137679 A137680 A137681 * A137683 A137684 A137685 KEYWORD nonn AUTHOR Gary W. Adamson, Feb 05 2008 STATUS approved

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Last modified April 6 18:45 EDT 2020. Contains 333286 sequences. (Running on oeis4.)