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A033453 "INVERT" transform of squares A000290. 4
1, 5, 18, 63, 221, 776, 2725, 9569, 33602, 117995, 414345, 1454992, 5109273, 17941453, 63002258, 221235399, 776878533, 2728045592, 9579660701, 33639430153, 118126444802, 414806579603, 1456612858961, 5114964721440, 17961439747441, 63072442405845, 221481854849938, 777743974335503, 2731084630047981 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Number of compositions of n+1 whose parts equal to q can be of q^2 kinds. Example: a(1)=5 because we have (2),(2'),(2"),(2'") and (1,1). Row sums of A105495. - Emeric Deutsch, Apr 10 2005

LINKS

Table of n, a(n) for n=0..28.

FORMULA

G.f.: (x+1)/(1-4x+2x^2-x^3).

MAPLE

read transforms; [seq(n^2, n=1..50)]; INVERT(%);

MATHEMATICA

nn=20; a=(x+x^2)/(1-x)^3; Drop[CoefficientList[Series[1/(1-a), {x, 0, nn}], x], 1]  (* Geoffrey Critzer, Aug 31 2012*)

CROSSREFS

Cf. A105495.

Sequence in context: A111567 A121050 A029869 * A284840 A222373 A147535

Adjacent sequences:  A033450 A033451 A033452 * A033454 A033455 A033456

KEYWORD

nonn

AUTHOR

N. J. A. Sloane.

STATUS

approved

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Last modified July 21 00:46 EDT 2017. Contains 289629 sequences.