[seqfan] Re: Help with A028247 Number of T-frame polyominoes with n cells

[Don Reble]

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> ...polyominoes which are integral rectangles with integral notches cut
> from two adjacent corners.

    I like that take, yielding sequence
	0,0,0,1,2,6,10,18,27,42,55,80,101,133,163,211,246,308,353,432,...
    but I get a(8)=18 instead of 19, etc. Did I miss one?

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-- 
Don Reble  djr at nk.ca