A056031 Numbers k such that k^22 == 1 (mod 23^2).

1, 28, 42, 63, 118, 130, 170, 177, 195, 255, 263, 266, 274, 334, 352, 359, 399, 411, 466, 487, 501, 528, 530, 557, 571, 592, 647, 659, 699, 706, 724, 784, 792, 795, 803, 863, 881, 888, 928, 940, 995, 1016, 1030, 1057, 1059, 1086, 1100, 1121, 1176, 1188

Offset: 1

Author

Robert G. Wilson v, Jun 08 2000

Keywords

• nonn

Links

• Amiram Eldar, Table of n, a(n) for n = 1..10000
• Index entries for linear recurrences with constant coefficients, signature (1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,-1).

Crossrefs

Cf. A056021, A056022, A056024, A056025, A056026, A056027, A056028, A056034, A056035.

Cf. A381319 (general case mod n^2).

Programs

Mathematica

x=23; Select[ Range[ 2000 ], PowerMod[ #, x-1, x^2 ]==1& ]

Formula

From Mike Sheppard, Feb 20 2025 : (Start)

a(n) = a(n-1) + a(n-22) - a(n-23).

a(n) = a(n-22) + 23^2.

a(n) ~ (23^2/22)*n. (End)