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A078436 Triangle read by rows in which n-th row counts multisets associated with hook partitions. 1
1, 2, 0, 3, 4, 0, 4, 6, 8, 0, 5, 8, 12, 16, 0, 6, 10, 16, 24, 32, 0, 7, 12, 20, 32, 48, 64, 0, 8, 14, 24, 40, 64, 96, 128, 0, 9, 16, 28, 48, 80, 128, 192, 256, 0, 10, 18, 32, 56, 96, 160, 256, 384, 512, 0, 11, 20, 36, 64, 112, 192, 320, 512, 768, 1024, 0, 12, 22, 40, 72, 128 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Row sums appear to be A077802. When more general partition types are included, such as 22^(n-4) yielding 9 18 36 72 ..., the array row sums becomes 1,2,7,18,50,118,301,... in agreement with A074141.

LINKS

Table of n, a(n) for n=1..71.

FORMULA

G.f.: x*y*(2-x)/(1-2*x*y)/(1-x)^2. - Vladeta Jovovic, Dec 31 2002

EXAMPLE

Triangle begins 1; 2,0; 3,4,0; 4,6,8,0; 5,8,12,16,0; ...

a(13) = 12 because we find 1 + 3 + 4 + 3 + 1 multisets of type 21^(n-2): they are 4; 14,24,34; 114,124,134,234; 1124,1134,1234; and 11234

CROSSREFS

Cf. A077802, A074139, A074141.

Sequence in context: A102389 A099091 A227595 * A209705 A181289 A229032

Adjacent sequences:  A078433 A078434 A078435 * A078437 A078438 A078439

KEYWORD

easy,nonn,tabl

AUTHOR

Alford Arnold, Dec 30 2002

EXTENSIONS

More terms from Vladeta Jovovic, Dec 31 2002

STATUS

approved

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Last modified March 21 10:00 EDT 2019. Contains 321368 sequences. (Running on oeis4.)