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A257609 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) = 2*x + 2. 12
1, 2, 2, 4, 16, 4, 8, 88, 88, 8, 16, 416, 1056, 416, 16, 32, 1824, 9664, 9664, 1824, 32, 64, 7680, 76224, 154624, 76224, 7680, 64, 128, 31616, 549504, 1999232, 1999232, 549504, 31616, 128, 256, 128512, 3739648, 22587904, 39984640, 22587904, 3739648, 128512, 256 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Row sums are: 1, 4, 24, 192, 1920, 23040, 322560, ... (see A002866).

LINKS

Table of n, a(n) for n=0..44.

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) = 2*x + 2.

EXAMPLE

1

2 2

4 16 4

8 88 88 8

16 416 1056 416 16

32 1824 9664 9664 1824 32

64 7680 76224 154624 76224 7680 64

128 31616 549504 1999232 1999232 549504 31616 128

256 128512 3739648 22587904 39984640 22587904 3739648 128512 256

512 518656 24494080 233058304 670901248 670901248 233058304 24494080 518656 512

CROSSREFS

Cf. A060187, A257611, A257613, A257615.

Cf. A038208, A256890, A257610, A257612, A257614, A257616, A257617, A257618, A257619.

Cf. similar sequences listed in A256890.

Sequence in context: A121221 A122598 A279069 * A087783 A176190 A106241

Adjacent sequences:  A257606 A257607 A257608 * A257610 A257611 A257612

KEYWORD

nonn,tabl

AUTHOR

Dale Gerdemann, May 03 2015

STATUS

approved

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Last modified February 27 15:59 EST 2020. Contains 332307 sequences. (Running on oeis4.)