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 A143971 Triangle read by rows, (3n-2) subsequences decrescendo 2
 1, 4, 1, 7, 4, 1, 10, 7, 4, 1, 13, 10, 7, 4, 1, 16, 13, 10, 7, 4, 1, 19, 16, 13, 10, 7, 4, 1, 22, 19, 16, 13, 10, 7, 4, 1, 25, 22, 19, 16, 13, 10, 7, 4, 1, 28, 25, 22, 19, 16, 13, 10, 7, 4, 1, 31, 28, 25, 22, 19, 16, 13, 10, 7, 4, 1 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Row sums = pentagonal numbers, A000326: (1, 5, 12, 22, 35,...). The alternating row sums lead to A032766 and the antidiagonal sums to A006578.  - Johannes W. Meijer, Sep 05 2013 LINKS FORMULA Triangle read by rows, (3n-2) subsequences decrescendo; 1<=k<=n. (1, 4, 7, 10, 13,...) in every column. T(n,k) = 3*n - 3*k + 1. EXAMPLE Triangle starts 1; 4, 1; 7, 4, 1; 10, 7, 4, 1; ... MAPLE T := (n, k) -> 3*n-3*k+1: seq(seq(T(n, k), k=1..n), n=1..11); # Johannes W. Meijer, Sep 05 2013 CROSSREFS Cf. A016777, A000326, A209634. Sequence in context: A335619 A037022 A037023 * A016688 A143972 A019651 Adjacent sequences:  A143968 A143969 A143970 * A143972 A143973 A143974 KEYWORD nonn,tabl AUTHOR Gary W. Adamson, Sep 06 2008 EXTENSIONS Terms a(17) and a(38) corrected and terms added by Johannes W. Meijer, Sep 05 2013 STATUS approved

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Last modified April 22 21:05 EDT 2021. Contains 343177 sequences. (Running on oeis4.)