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A213835 Rectangular array:  (row n) = b**c, where b(h) = h, c(h) = 4*n-7+4*h, n>=1, h>=1, and ** = convolution. 6
1, 7, 5, 22, 19, 9, 50, 46, 31, 13, 95, 90, 70, 43, 17, 161, 155, 130, 94, 55, 21, 252, 245, 215, 170, 118, 67, 25, 372, 364, 329, 275, 210, 142, 79, 29, 525, 516, 476, 413, 335, 250, 166, 91, 33, 715, 705, 660, 588, 497, 395 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Principal diagonal: A172078.

Antidiagonal sums: A051797.

Row 1, (1,2,3,4,5,...)**(1,5,9,13,...): A002412.

Row 2, (1,2,3,4,5,...)**(5,9,13,17,...): (4*k^3 + 15*k^2 - 11*k)/6.

Row 3, (1,2,3,4,5,...)**(9,13,17,21,...): (4*k^3 + 27*k^2 - 23*k)/6

For a guide to related arrays, see A212500.

LINKS

Clark Kimberling, Antidiagonals n = 1..60, flattened.

FORMULA

T(n,k) = 4*T(n,k-1)-6*T(n,k-2)+4*T(n,k-3)-T(n,k-4).

G.f. for row n: f(x)/g(x), where f(x) = x*((4*n-3) + (4*n-7)*x) and g(x) = (1-x)^4.

EXAMPLE

Northwest corner (the array is read by falling antidiagonals):

1....7....22....50....95

5....19...46....90....155

9....31...70....130...215

13...43...94....170...275

17...55...118...210...335

21...67...142...250...395

MATHEMATICA

b[n_]:=n; c[n_]:=4n-3;

t[n_, k_]:=Sum[b[k-i]c[n+i], {i, 0, k-1}]

TableForm[Table[t[n, k], {n, 1, 10}, {k, 1, 10}]]

Flatten[Table[t[n-k+1, k], {n, 12}, {k, n, 1, -1}]]

r[n_]:=Table[t[n, k], {k, 1, 60}] (* A213835 *)

Table[t[n, n], {n, 1, 40}] (* A172078 *)

s[n_]:=Sum[t[i, n+1-i], {i, 1, n}]

Table[s[n], {n, 1, 50}] (* A051797 *)

CROSSREFS

Cf. A212500.

Cf. A304659 (first lower diagonal).

Sequence in context: A179118 A166639 A078747 * A145396 A263825 A226661

Adjacent sequences:  A213832 A213833 A213834 * A213836 A213837 A213838

KEYWORD

nonn,tabl,easy

AUTHOR

Clark Kimberling, Jul 04 2012

STATUS

approved

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Last modified March 26 01:08 EDT 2019. Contains 321479 sequences. (Running on oeis4.)