A391870 Records in A210693.

4, 11, 18, 23, 48, 221, 2003, 2927, 4256, 10063, 19296, 23618, 57576, 70852, 125558, 181586, 211101, 593286, 742861, 1384104, 1938665, 2103883, 2341224, 2469308, 2757948, 3419961, 4763217, 8229111, 9344114, 13314161, 14701551, 20380851, 22849565, 31757205, 34607267, 46773074

Offset

1,1

Links

Table of n, a(n) for n=1..36.

Formula

a(n) = A210693(A391871(n)).

Mathematica

A210693[n_] := Module[{k = 0}, While[++k == n || PowerMod[n, k, 2*k + 1] != PowerMod[k, n, #]] & [2*n + 1]; k];
Module[{rec = 0}, Table[If[# > rec, rec = #, Nothing] & [A210693[m]], {m, 10000}]]

Crossrefs

Cf. A210693, A391871.

Sequence in context: A050395 A368424 A059771 * A325618 A361131 A043409

Adjacent sequences: A391867 A391868 A391869 * A391871 A391872 A391873

Keyword

nonn

Author

Paolo Xausa, Dec 21 2025

Extensions

a(27)-a(36) from Michael S. Branicky, Dec 22 2025

Status

approved