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A091934 Number of dual isomorphisms on [ n,n* ]. 1
1, 3, 4, 7, 8, 10, 11, 15, 19, 24, 25, 30 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

I would like a better definition. - N. J. A. Sloane.

LINKS

Table of n, a(n) for n=1..12.

Jon Perry, Trees of height 2 (bottom of page) [wayback cached version]

CROSSREFS

Cf. A220096.

Sequence in context: A184835 A184823 A242921 * A178482 A284658 A286340

Adjacent sequences:  A091931 A091932 A091933 * A091935 A091936 A091937

KEYWORD

nonn,more,uned,obsc

AUTHOR

Jon Perry, Mar 11 2004

STATUS

approved

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Last modified July 21 04:40 EDT 2019. Contains 325189 sequences. (Running on oeis4.)