A128835 Numbers n such that n^n == 2 (mod 7), or 7 divides n^n-2.

11, 16, 32, 37, 38, 40, 53, 58, 74, 79, 80, 82, 95, 100, 116, 121, 122, 124, 137, 142, 158, 163, 164, 166, 179, 184, 200, 205, 206, 208, 221, 226, 242, 247, 248, 250, 263, 268, 284, 289, 290, 292, 305, 310, 326, 331, 332, 334, 347, 352, 368, 373, 374, 376, 389

Offset

1,1

Comments

First differences have a cycle {5,16,5,1,2,13}.

Links

Table of n, a(n) for n=1..55.

Formula

a(1)=11, a(2)=16, a(3)=32, a(4)=37, a(5)=38, a(6)=40; n>=7: a(n)=a(n-6)+42.

Example

11^11=285311670611=7*40758810087+2,
16^16=18446744073709551616=7*2635249153387078802+2.

Mathematica

Select[Range[500], PowerMod[ #, #, 7]==2&]

Crossrefs

Sequence in context: A166451 A109307 A327752 * A316171 A184064 A302207

Adjacent sequences: A128832 A128833 A128834 * A128836 A128837 A128838

Keyword

nonn

Author

Zak Seidov, Apr 14 2007

Status

approved