A087025 -id:A087025 - cp's OEIS frontend

A087026 Euler's totient of n-th cyclic number.

77760, 1382399778816000, 98221093640386560, 1053590173895849103360, 821095240766161265049600000, 511883170649353472639948811682935064652736000, 410719109641406326635474611575828305116907342385175347200

Offset: 1

Reinhard Zumkeller, Jul 30 2003

nonn

Calculated with Dario Alpern's ECM.

Extended using factors of 10^(A001913(n)-1)-1, see Kamada link.

Max Alekseyev, Table of n, a(n) for n = 1..51 (first 42 terms from Ray Chandler)
Dario A. Alpern, Factorization using the Elliptic Curve Method.
Makoto Kamada, Factorizations of 11...11 (Repunit)
Eric Weisstein's World of Mathematics, Cyclic Number.
Eric Weisstein's World of Mathematics, Totient Function.

Cf. A001913, A087020, A087021, A087022, A087023, A087024, A087025.

a(n) = A000010(A004042(n+1)).

a(12)-a(42) from Ray Chandler, Nov 16 2011

A087020 Greatest prime factor of n-th cyclic number.

Original entry on oeis.org

37, 5882353, 333667, 513239, 121499449, 11111111111111111111111, 154083204930662557781201849, 39526741, 9999999900000001, 59779577156334533866654838281, 119968369144846370226083377, 8396862596258693901610602298557167100076327481

Offset: 1

Reinhard Zumkeller, Jul 30 2003

nonn

A004042(n) factorized with Dario Alpern's ECM.

Extended using factors of 10^(A001913(n)-1)-1, see Kamada link.

			A004042(2) = 142857 = 37*13*11*3^3, therefore a(1) = 37.

Max Alekseyev, Table of n, a(n) for n = 1..51 (first 42 terms from Ray Chandler)
Dario A. Alpern, Factorization using the Elliptic Curve Method.
Makoto Kamada, Factorizations of 11...11 (Repunit)
Eric Weisstein's World of Mathematics, Cyclic Number

Cf. A001913, A087021, A087022, A087023, A087024, A087025, A087026.

a(n) = A006530(A004042(n+1)).

a(12) from Ray Chandler, Nov 16 2011

A087024 Number of divisors of n-th cyclic number.

Original entry on oeis.org

32, 384, 1280, 576, 1536, 384, 1536, 4194304, 16777216, 3538944, 1769472, 110592, 221184, 13824, 6912, 48318382080, 9663676416, 3538944, 75497472, 14155776, 56623104, 884736, 55296, 57982058496, 3710851743744, 37748736, 695784701952, 27648, 27648, 2654208

Offset: 1

Reinhard Zumkeller, Jul 30 2003

nonn

Calculated with Dario Alpern's ECM.

Extended using factors of 10^(A001913(n)-1)-1, see Kamada link.

Max Alekseyev, Table of n, a(n) for n = 1..51 (first 42 terms from Ray Chandler)
Dario A. Alpern, Factorization using the Elliptic Curve Method.
Makoto Kamada, Factorizations of 11...11 (Repunit)
Eric Weisstein's World of Mathematics, Cyclic Number
Eric Weisstein's World of Mathematics, Divisor Function

Cf. A001913, A087020, A087021, A087022, A087023, A087025, A087026.

a(n) = A000005(A004042(n+1)).

a(12)-a(42) from Ray Chandler, Nov 16 2011

A087023 Maximal exponent in prime factorization of n-th cyclic number.

Original entry on oeis.org

3, 2, 4, 2, 2, 2, 2, 3, 3, 5, 2, 2, 2, 2, 2, 4, 3, 3, 3, 2, 2, 2, 2, 3, 3, 3, 5, 2, 2, 2, 5, 2, 7, 2, 3, 2, 2, 5, 3, 4, 2, 3, 2, 2, 2, 3, 3, 2, 6, 2, 3

Offset: 1

Reinhard Zumkeller, Jul 30 2003

A004042(n) factorized with Dario Alpern's ECM.

Extended using factors of 10^(A001913(n)-1)-1, see Kamada link.

			A004042(2) = 142857 = 37*13*11*3^3, therefore a(1) = 3.

Dario A. Alpern, Factorization using the Elliptic Curve Method.
Makoto Kamada, Factorizations of 11...11 (Repunit)
Eric Weisstein's World of Mathematics, Cyclic Number

Cf. A001913, A087020, A087021, A087022, A087024, A087025, A087026.

a(n) = A051903(A004042(n+1)).

a(12)-a(42) from Ray Chandler, Nov 16 2011

a(43)-a(51) from Max Alekseyev, May 14 2022

cp's OEIS Frontend

A087026 Euler's totient of n-th cyclic number.

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A087020 Greatest prime factor of n-th cyclic number.

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A087024 Number of divisors of n-th cyclic number.

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A087023 Maximal exponent in prime factorization of n-th cyclic number.

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