login
This site is supported by donations to The OEIS Foundation.
Logo

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A030653 n^3*a(n) is number of circles in complex projective plane tangent to three smooth curves of degree n in general position. 1
4, 23, 60, 121, 212, 339, 508, 725, 996, 1327, 1724, 2193, 2740, 3371, 4092, 4909, 5828, 6855, 7996, 9257, 10644, 12163, 13820, 15621, 17572, 19679, 21948, 24385, 26996, 29787, 32764, 35933, 39300, 42871, 46652, 50649, 54868, 59315 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

REFERENCES

See formula for enumeration of contacts in Fulton-Kleiman-MacPherson (pp. 156-196 of Lect. Notes Math. n.997).

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

FORMULA

a(n)=n^3+3*n^2+3*n-3.

PROG

(MAGMA) [n^3+3*n^2+3*n-3: n in [1..45]]; // Vincenzo Librandi, Jun 30 2011

CROSSREFS

Sequence in context: A030716 A106684 A179628 * A085505 A065972 A132112

Adjacent sequences:  A030650 A030651 A030652 * A030654 A030655 A030656

KEYWORD

nonn,nice

AUTHOR

Paolo Dominici (pl.dm(AT)libero.it)

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 16 17:11 EST 2012. Contains 205938 sequences.