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A246695 Row sums of the triangular array A246694. 7
1, 3, 9, 18, 35, 57, 91, 132, 189, 255, 341, 438, 559, 693, 855, 1032, 1241, 1467, 1729, 2010, 2331, 2673, 3059, 3468, 3925, 4407, 4941, 5502, 6119, 6765, 7471, 8208, 9009, 9843, 10745, 11682, 12691, 13737, 14859, 16020, 17261, 18543, 19909, 21318, 22815 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Also partial sums of A257083. - Reinhard Zumkeller, Apr 17 2015

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 0..10000

FORMULA

Conjectured linear recurrence:  a(n) = 2*a(n-1) + a(n-2) - 4*a(n-3) + a(n-4) + 2*a(n-5) - a(n-6), with a(0) = 1, a(1) = 3, a(2) = 9, a(3) = 18, a(4) = 35, a(5) = 57, a(6) = 91.

Conjectured g.f.:  (1 + x + 2 x^2 + x^3 + x^4)/((x - 1)^4 (x + 1)^2).

EXAMPLE

First 5 rows of A246694 preceded by sums

sum = 1: ...... 1

sum = 3: ...... 1 ... 2

sum = 9: ...... 3 ... 2 ... 4

sum = 18: ..... 3 ... 5 ... 4 ... 6

sum = 35: ..... 7 ... 5 ... 8 ... 6 ... 9

MATHEMATICA

z = 25; t[0, 0] = 1; t[1, 0] = 1; t[1, 1] = 2;

t[n_, 0] := If[OddQ[n], t[n - 1, n - 2] + 1, t[n - 1, n - 1] + 1];

t[n_, 1] := If[OddQ[n], t[n - 1, n - 1] + 1, t[n - 1, n - 2] + 1];

t[n_, k_] := t[n, k - 2] + 1; A246695 = Table[Sum[t[n, k], {k, 0, n}], {n, 0, z}]

PROG

(Haskell)

a246695 n = a246695_list !! n

a246695_list = scanl1 (+) a257083_list

-- Reinhard Zumkeller, Apr 17 2015

CROSSREFS

Cf. A246694, A246705, A246706.

Cf. A257083.

Sequence in context: A210970 A293406 A295862 * A132920 A127645 A000241

Adjacent sequences:  A246692 A246693 A246694 * A246696 A246697 A246698

KEYWORD

nonn,easy

AUTHOR

Clark Kimberling, Sep 01 2014

EXTENSIONS

Corrected and edited by M. F. Hasler, Nov 17 2014

STATUS

approved

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Last modified October 20 02:35 EDT 2019. Contains 328244 sequences. (Running on oeis4.)