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A350176
Numbers m such that binomial(m, 3) divides binomial(3^m-2, 3).
2
3, 5, 7, 17, 79, 97, 257, 457, 65537, 677041, 1354081, 7812169, 13650001, 21381361, 65246161, 134246401, 242235841, 277032001, 393414001, 468930001, 793605121, 859560241, 886966081
OFFSET
1,1
COMMENTS
Are all terms prime numbers?
MATHEMATICA
Select[Range[3, 10^5], Divisible[Binomial[3^# - 2, 3], Binomial[#, 3]] &] (* Amiram Eldar, Dec 18 2021 *)
PROG
(Magma) [n: n in [3..10^4] | IsZero(Binomial(3^n-2, 3) mod Binomial(n, 3))];
(PARI) isok(m) = if (m>=3, (binomial(3^m-2, 3) % binomial(m, 3)) == 0); \\ Michel Marcus, Dec 19 2021
(PARI) isok(m) = if (m>2, my(md = Mod(3, m^3 - 3*m^2 + 2*m)^m); (md^3 - 9*md^2 + 26*md - 24) == 0); \\ Michel Marcus, Dec 28 2021
CROSSREFS
Supersequence of A019434.
Cf. A069051 (binomial(k,2) divides binomial(2^k-1, 2)?).
Sequence in context: A215684 A229132 A270779 * A248796 A247164 A064080
KEYWORD
nonn,more
AUTHOR
EXTENSIONS
a(11)-a(20) from Michel Marcus, Dec 27 2021
a(21)-a(23) from Michel Marcus, Dec 28 2021
STATUS
approved