A056102 - OEIS

A056102

Numbers k such that k^4 == 1 (mod 5^5).

1, 1068, 2057, 3124, 3126, 4193, 5182, 6249, 6251, 7318, 8307, 9374, 9376, 10443, 11432, 12499, 12501, 13568, 14557, 15624, 15626, 16693, 17682, 18749, 18751, 19818, 20807, 21874, 21876, 22943, 23932, 24999, 25001, 26068, 27057, 28124

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OFFSET

1,2

LINKS

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

Index entries for linear recurrences with constant coefficients, signature (1,0,0,1,-1).

FORMULA

From Chai Wah Wu, Jun 21 2020: (Start)

a(n) = a(n-1) + a(n-4) - a(n-5) for n > 5.

G.f.: x*(x^4 + 1067*x^3 + 989*x^2 + 1067*x + 1)/(x^5 - x^4 - x + 1). (End)

MATHEMATICA

x=5; Select[ Range[ 50000 ], PowerMod[ #, x-1, x^5 ]==1& ]

PROG

(PARI) for(n=1, 30000, if(n^4%5^5==1, print1(n, ", "))) \\ Hugo Pfoertner, Jun 21 2020

CROSSREFS

Sequence in context: A224457 A123211 A023078 * A218564 A234880 A218565

Adjacent sequences: A056099 A056100 A056101 * A056103 A056104 A056105

KEYWORD

nonn,easy

AUTHOR

Robert G. Wilson v, Jun 08 2000

STATUS

approved