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

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A045976 A product related to n-th roots of 1. 0
1, 1, 0, 9, 121, 2704, 118336, 4092529, 0, 97734390625, 69057113823721, 61675735716000000, 120510849036513735801, 204044070747203744272384, 0, 12086640655039701533948077217761, 424809992547069296975659357323606889 (list; graph; refs; listen; history; internal format)
OFFSET

1,4

COMMENTS

a(3*(2*k+1)) = 0 for all k because there are some 3rd roots involved.

REFERENCES

related work:

(a) Dickson's  History of the Theory of Numbers, Vol II,

page 756, lines -5 to  -1, and page 757, lines 1 to 4:

Some related work of E. Wendt is described.

(b) Idem (a), but page 757, lines 14 to 24:

Some related work of G. B. Mathews (in 1895) is described.

(c) Mathews ' work  cited in (b) appears (in French)

in page 132, lines 1 to 13 of R Nogues, Theoreme de Fermat

Son Histoire, reprint (1992) Jacques Gabay's edition of the original of 1932.

All this is related to "the first case" of Fermat's Theorem

as worked by mathematiciens at the end of 19th century.

FORMULA

a(n) = product ((1+u)^n +1), where u^n = 1, u != 1.

PROG

(PARI) a(n)=sum(k=1, n-1, (1+exp(2*Pi*I/n))^n+1) \\ Charles R Greathouse IV, May 13, 2011

CROSSREFS

Sequence in context: A202835 A050353 A112941 * A053889 A087584 A199139

Adjacent sequences:  A045973 A045974 A045975 * A045977 A045978 A045979

KEYWORD

nonn

AUTHOR

Luis H. Gallardo (Luis.Gallardo(AT)univ-brest.fr)

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 20:35 EST 2012. Contains 205962 sequences.