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A257619 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) = 9*x + 2. 9
1, 2, 2, 4, 44, 4, 8, 564, 564, 8, 16, 6436, 22560, 6436, 16, 32, 71404, 637844, 637844, 71404, 32, 64, 786948, 15470232, 36994952, 15470232, 786948, 64, 128, 8660012, 346391196, 1660722424, 1660722424, 346391196, 8660012, 128 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Row sums are: 1, 4, 52, 1144, 35464, 1418560, 69509440, 4031547520, 270113683840, 20528639971840, ... (see A144829).

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) = 9*x + 2.

EXAMPLE

1

2 2

4 44 4

8 564 564 8

16 6436 22560 6436 16

32 71404 637844 637844 71404 32

64 786948 15470232 36994952 15470232 786948 64

128 8660012 346391196 1660722424 1660722424 346391196 8660012 128

PROG

(PARI) f(x) = 9*x + 2;

t(n, m) = if ((n<0) || (m<0), 0, if ((n==0) && (m==0), 1, f(m)*t(n-1, m) + f(n)*t(n, m-1)));

tabl(nn) = {for (n=0, nn, for (k=0, n, print1(t(n-k, k), ", "); ); print(); ); } \\ Michel Marcus, May 23 2015

CROSSREFS

Cf. A257608.

Cf. A038208, A256890, A257609, A257610, A257612, A257614, A257616, A257617, A257618.

Similar sequences listed in A256890.

Sequence in context: A309344 A257618 A088895 * A075806 A295580 A177956

Adjacent sequences:  A257616 A257617 A257618 * A257620 A257621 A257622

KEYWORD

nonn,tabl

AUTHOR

Dale Gerdemann, May 09 2015

STATUS

approved

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Last modified January 18 19:32 EST 2020. Contains 331029 sequences. (Running on oeis4.)