A220075 Partial sums in rows of A220073, triangle read by rows.

1, 1, 3, 2, 3, 6, 3, 4, 6, 10, 4, 6, 7, 10, 15, 5, 8, 9, 11, 15, 21, 6, 10, 12, 13, 16, 21, 28, 7, 12, 15, 16, 18, 22, 28, 36, 8, 14, 18, 20, 21, 24, 29, 36, 45, 9, 16, 21, 24, 25, 27, 31, 37, 45, 55, 10, 18, 24, 28, 30, 31, 34, 39, 46, 55, 66, 11, 20, 27

Offset

1,3

Comments

T(n,k) = sum(A220073(n,i): i=1..k).

Links

Reinhard Zumkeller, Table of n, a(n) for n = 1..7260

Mathematica

A[n_, k_] := If[k == 1, n, If[k == n, n-1, Abs[2k-n-If[2k <= n+1, 2, 1]]]];
A220073[n_, k_] := A[n, n-k+1];
T[n_, k_] := Sum[A220073[n, i], {i, 1, k}];
Table[T[n, k], {n, 1, 12}, {k, 1, n}] // Flatten (* Jean-François Alcover, Sep 27 2021 *)

Prog

(Haskell)
a220075 n k = a220075_tabl !! (n-1) !! (k-1)
a220075_row n = a220075_tabl !! (n-1)
a220075_tabl = map (scanl1 (+)) a220073_tabl

Crossrefs

Cf. A000027 (left edge), A000217 (right edge), A002061 (central terms), A019298 (row sums); A220053.

Sequence in context: A021313 A240162 A113128 * A266593 A130459 A323621

Adjacent sequences: A220072 A220073 A220074 * A220076 A220077 A220078

Keyword

nonn,tabl

Author

Reinhard Zumkeller, Dec 03 2012

Status

approved