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!)
A218341 Triangle T(n,k) of orders of degree-n irreducible polynomials over GF(29) listed in ascending order. 4
1, 2, 4, 7, 14, 28, 3, 5, 6, 8, 10, 12, 15, 20, 21, 24, 30, 35, 40, 42, 56, 60, 70, 84, 105, 120, 140, 168, 210, 280, 420, 840, 13, 26, 52, 67, 91, 134, 182, 268, 364, 469, 871, 938, 1742, 1876, 3484, 6097, 12194, 24388, 16, 48, 80, 112, 240, 336, 421, 560 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
LINKS
Eric Weisstein's World of Mathematics, Irreducible Polynomial
Eric Weisstein's World of Mathematics, Polynomial Order
FORMULA
T(n,k) = k-th smallest element of M(n) = {d : d|(29^n-1)} \ U(n-1) with U(n) = M(n) union U(n-1) if n>0, U(0) = {}.
EXAMPLE
Triangle begins:
: 1, 2, 4, 7, 14, 28;
: 3, 5, 6, 8, 10, 12, 15, ...
: 13, 26, 52, 67, 91, 134, 182, ...
: 16, 48, 80, 112, 240, 336, 421, ...
: 732541, 1465082, 2930164, 5127787, 10255574, 20511148;
MAPLE
with(numtheory):
M:= proc(n) M(n):= divisors(29^n-1) minus U(n-1) end:
U:= proc(n) U(n):= `if`(n=0, {}, M(n) union U(n-1)) end:
T:= n-> sort([M(n)[]])[]:
seq(T(n), n=1..5);
MATHEMATICA
M[n_] := M[n] = Divisors[29^n-1] ~Complement~ U[n-1];
U[n_] := U[n] = If[n == 0, {}, M[n] ~Union~ U[n-1]];
T[n_] := Sort[M[n]];
Table[T[n], {n, 1, 5}] // Flatten (* Jean-François Alcover, Feb 12 2023, after Alois P. Heinz *)
CROSSREFS
Column k=10 of A212737.
Column k=1 gives: A218364.
Row lengths are A212957(n,29).
Sequence in context: A119267 A144978 A018254 * A018660 A018692 A161713
KEYWORD
nonn,tabf,look
AUTHOR
Alois P. Heinz, Oct 26 2012
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 April 19 09:23 EDT 2024. Contains 371782 sequences. (Running on oeis4.)