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

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A022815 Number of terms in 5th derivative of a function composed with itself n times. 2
1, 7, 23, 55, 110, 196, 322, 498, 735, 1045, 1441, 1937, 2548, 3290, 4180, 5236, 6477, 7923, 9595, 11515, 13706, 16192, 18998, 22150, 25675, 29601, 33957, 38773, 44080, 49910, 56296, 63272, 70873, 79135, 88095, 97791, 108262, 119548, 131690 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

REFERENCES

W. C. Yang (yang(AT)math.wisc.edu), Derivatives of self-compositions of functions, preprint, 1997.

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..10000

FORMULA

a(n) = n*(n+1)*(n^2+13*n-2)/24. - John W. Layman (layman(AT)math.vt.edu), Apr 27 2000

G.f.: x*(1-2*x^2+2*x)/(1-x)^5 [From Maksym Voznyy (voznyy(AT)mail.ru), Aug 11 2009]

PROG

(MAGMA) [n*(n+1)*(n^2+13*n-2)/24: n in [1..40]]; // Vincenzo Librandi, Oct 10 2011

CROSSREFS

Cf. A008778, A022811-A022818, A024207-A024210.

Sequence in context: A098334 A038796 A004068 * A172252 A027116 A151718

Adjacent sequences:  A022812 A022813 A022814 * A022816 A022817 A022818

KEYWORD

nonn

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com).

EXTENSIONS

G.f. proposed by Maksym Voznyy checked and corrected by R. J. Mathar, Sep 16 2009.

More terms from Christian G. Bower (bowerc(AT)usa.net), Aug 15 1999.

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 17 21:13 EST 2012. Contains 206085 sequences.