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A257627 Triangle read by rows: T(n,k) = t(n-k, k); t(n,m) = f(m)*t(n-1,m) + f(n)*t(n,m-1), where f(x) = 7*x + 3. 8
1, 3, 3, 9, 60, 9, 27, 753, 753, 27, 81, 8178, 25602, 8178, 81, 243, 84291, 631506, 631506, 84291, 243, 729, 852144, 13348623, 30312288, 13348623, 852144, 729, 2187, 8554245, 259308063, 1141302225, 1141302225, 259308063, 8554245, 2187 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Row sums are: 1, 6, 78, 1560, 42120, 1432080, 58715280, 2818333440, 155008339200, 9610517030400, ... (see A049209).

LINKS

Table of n, a(n) for n=0..35.

FORMULA

T(n,k) = t(n-k, k); t(0,0) = 1, t(n,m) = 0 if n < 0 or m < 0, else t(n,m) = f(m)*t(n-1,m) + f(n)*t(n,m-1), where f(x) = 7*x + 3.

EXAMPLE

1

3 3

9 60 9

27 753 753 27

81 8178 25602 8178 81

243 84291 631506 631506 84291 243

729 852144 13348623 30312288 13348623 852144 729

2187 8554245 259308063 1141302225 1141302225 259308063 8554245 2187

CROSSREFS

Cf. A142462, A257617.

Cf. A038221, A257180, A257611, A257620, A257621, A257623, A257625.

See similar sequences listed in A256890.

Sequence in context: A257623 A257625 A216147 * A115564 A122961 A165421

Adjacent sequences:  A257624 A257625 A257626 * A257628 A257629 A257630

KEYWORD

nonn,tabl

AUTHOR

Dale Gerdemann, May 10 2015

STATUS

approved

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Last modified April 8 12:11 EDT 2020. Contains 333314 sequences. (Running on oeis4.)