A371730 Indices of records in A371729: numbers k with A371729(k) > A371729(m) for all m < k.

2, 5, 9, 13, 17, 25, 37, 41, 49, 73, 97, 109, 161, 181, 289, 307, 361, 433, 529, 701, 841, 881, 961, 1189, 1369, 1681, 1849, 2209, 2393, 2449, 3277, 3457, 3781, 4096, 4159, 4841, 4861, 5741, 5851, 6049, 7921, 10201, 11449, 11881, 15049, 15401, 19601, 27026, 32768

Offset: 1

Author

Amiram Eldar, Apr 05 2024

Keywords

• nonn

Comments

The corresponding record values are 0, 1, 2, 3, 4, 5, 7, 8, 9, 11, 12, ... (see the link for more values).

Links

• Amiram Eldar, Table of n, a(n) for n = 1..69 (terms below 10^6)
• Amiram Eldar, Table of n, a(n), A371729(a(n)) for n = 1..69.
• Wikipedia, Pseudoprime.
• Index entries for sequences related to pseudoprimes.

Crossrefs

Cf. A371729.

Programs

Mathematica

f[k_] := Count[Range[4, k - 1], ?(CompositeQ[#] && PowerMod[k, # - 1, #] == 1 &)]; seq[kmax] := Module[{s = {}, fm = -1, f1}, Do[f1 = f[k]; If[f1 > fm, fm = f1; AppendTo[s, k]], {k, 2, kmax}]; s]; seq[2500]

PARI

f(n) = {my(c=0); forcomposite(k = 4, n-1, if(Mod(n, k)^(k-1) == 1, c++)); c;}
lista(kmax) = {my(fm = -1, f1); for(k = 2, kmax, f1 = f(k); if(f1 > fm, fm = f1; print1(k, ", ")));}