login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A232057 Numbers n such that S(24*(3*n-1)) <> 16*(3*n-1) mod 24*(3*n-1)  where S(n) := sum_{0<=a<n, 0<=b<n} (a+b*i)^n and i is the imaginary unit. 1
5, 19, 37, 47, 61, 75 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..6.

MATHEMATICA

fu[n_] := fu[n] = Mod[Sum[PowerMod[i + j I, n, n], {i, 0, n - 1}, {j, 0, n - 1}], n]; Table[If[! fu[24(3n - 1)]/(3n - 1) == 16, Print[n]; n], {n, 1, 40}]

CROSSREFS

Cf. A230308, A230309, A230310, A232056.

Sequence in context: A289289 A213631 A242589 * A031093 A297750 A285226

Adjacent sequences:  A232054 A232055 A232056 * A232058 A232059 A232060

KEYWORD

nonn,more,hard

AUTHOR

José María Grau Ribas, Nov 17 2013

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified August 10 06:08 EDT 2022. Contains 356029 sequences. (Running on oeis4.)