cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-6 of 6 results.

A262101 Pseudoprimes to base 4, written in base 4.

Original entry on oeis.org

33, 1111, 1123, 11111, 12303, 13003, 20301, 22011, 22333, 101101, 103133, 103313, 111223, 120231, 122133, 123001, 131203, 131301, 133333, 200113, 212201, 222031, 230011, 300331, 303031, 310213, 321203, 333001, 1010101, 1010103, 1021021, 1022323, 1023323, 1111111, 1112233, 1213021, 1213303, 1330111, 2002001, 2010201, 2013313, 2023033, 2031211, 2032223
Offset: 1

Views

Author

Abdul Gaffar Khan, Sep 11 2015

Keywords

Links

Crossrefs

Cf. A007090 (numbers in base 4), A020136 (pseudoprimes to base 4).
Cf. A258189, A262102, A262103, A262104, A262105, A262154.

Programs

  • Mathematica
    BaseForm[Select[Range[4096], Not[PrimeQ[#]] && PowerMod[4, # - 1, #] == 1 &], 4]
  • PARI
    lista(nn, b=4) = {for (n=1, nn, if (Mod(b, n)^(n-1)==1 && !ispseudoprime(n) && n>1, print1(subst(Pol(digits(n,b), x), x, 10), ", ");););} \\ Michel Marcus, Sep 30 2015

Formula

a(n) = A007090(A020136(n)).

A262102 Pseudoprimes to base 5, written in base 5.

Original entry on oeis.org

4, 444, 1332, 4221, 11111, 22131, 23404, 30031, 42241, 112443, 133321, 134421, 140122, 140411, 202401, 214244, 222223, 224104, 241121, 304011, 323131, 331401, 402201, 404041, 411313, 421411, 434411, 1001001, 1001331, 1010142, 1032032, 1140421, 1212131, 1224103, 1233321, 1302302, 1302401, 1414331, 1421124, 1440143
Offset: 1

Views

Author

Abdul Gaffar Khan, Sep 11 2015

Keywords

Links

Crossrefs

Cf. A007091 (numbers in base 5), A005936 (pseudoprimes to base 5).
Cf. A258189, A262101, A262103, A262104, A262105, A262154.

Programs

  • Mathematica
    base = 5; t = {}; n = 1;
While[Length[t] < 40, n++;
If[! PrimeQ[n] && PowerMod[base, n - 1, n] == 1,
  AppendTo[t, FromDigits@IntegerDigits[n, 5]]]]; t
  • PARI
    lista(nn, b=5) = {for (n=1, nn, if (Mod(b, n)^(n-1)==1 && !ispseudoprime(n) && n>1, print1(subst(Pol(digits(n,b), x), x, 10), ", ");););} \\ Michel Marcus, Sep 30 2015

Formula

a(n) = A007091(A005936(n)).

A262103 Pseudoprimes to base 6, written in base 6.

Original entry on oeis.org

55, 505, 1001, 1221, 2121, 5041, 5051, 5501, 10101, 12001, 15225, 20301, 21021, 23501, 24301, 24341, 30041, 31031, 32451, 42241, 50125, 50321, 101101, 102421, 105131, 111111, 113425, 121001, 121101, 123041, 123321, 132305, 150135, 152021, 201201, 204445, 212121, 221001, 222401, 232401
Offset: 1

Views

Author

Abdul Gaffar Khan, Sep 11 2015

Keywords

Links

Crossrefs

Cf. A007092 (numbers in base 6), A005937 (pseudoprimes to base 6).
Cf. A258189, A262101, A262102, A262104, A262105, A262154.

Programs

  • Mathematica
    base = 6; t = {}; n = 1;
While[Length[t] < 40, n++;
If[! PrimeQ[n] && PowerMod[base, n - 1, n] == 1,
  AppendTo[t, FromDigits@IntegerDigits[n, 6]]]]; t
  • PARI
    lista(nn, b=6) = {for (n=1, nn, if (Mod(b, n)^(n-1)==1 && !ispseudoprime(n) && n>1, print1(subst(Pol(digits(n,b), x), x, 10), ", ");););} \\ Michel Marcus, Sep 30 2015

Formula

a(n) = A007092(A005937(n)).

A262104 Pseudoprimes to base 7, written in base 7.

Original entry on oeis.org

6, 34, 643, 1431, 2023, 2245, 3136, 5215, 6061, 6601, 10121, 12361, 16123, 20032, 25345, 33155, 41545, 42601, 42652, 44122, 45406, 50026, 54561, 56035, 66522, 66666, 105403, 110254, 112612, 113345, 113356, 123616, 135206, 140011, 151142, 151354, 153022, 153101, 153352, 155554
Offset: 1

Views

Author

Abdul Gaffar Khan, Sep 11 2015

Keywords

Links

Crossrefs

Cf. A005938 (pseudoprimes to base 7), A007093 (numbers in base 7).
Cf. A258189, A262101, A262102, A262103, A262105, A262154.

Programs

  • Mathematica
    base = 7; t = {}; n = 1;
While[Length[t] < 40, n++;
If[! PrimeQ[n] && PowerMod[base, n - 1, n] == 1,
  AppendTo[t, FromDigits@IntegerDigits[n, 7]]]]; t
FromDigits[IntegerDigits[#,7]]&/@Select[Range[40000],CompositeQ[#] && PowerMod[ 7,#-1,#]==1&] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Feb 24 2018 *)
  • PARI
    lista(nn, b=7) = {for (n=1, nn, if (Mod(b, n)^(n-1)==1 && !ispseudoprime(n) && n>1, print1(subst(Pol(digits(n,b), x), x, 10), ", ");););} \\ Michel Marcus, Sep 30 2015

Formula

a(n) = A007093(A005938(n)).

A262105 Pseudoprimes to base 8, written in base 8.

Original entry on oeis.org

11, 25, 55, 77, 101, 151, 165, 205, 231, 347, 421, 525, 741, 777, 1061, 1111, 1205, 1213, 1535, 1665, 1751, 2121, 2401, 2525, 2553, 2611, 3005, 3161, 3175, 3301, 3371, 3561, 3777, 4171, 4641, 4705, 5215, 5405, 6111, 6143
Offset: 1

Views

Author

Abdul Gaffar Khan, Sep 11 2015

Keywords

Links

Crossrefs

Cf. A007094 (Numbers in base 8), A020137 (Pseudoprimes to base 8).
Cf. A258189, A262101, A262102, A262103, A262104, A262154.

Programs

  • Mathematica
    base = 8; t = {}; n = 1;
  While[Length[t] < 40, n++;
   If[! PrimeQ[n] && PowerMod[base, n - 1, n] == 1, AppendTo[t, FromDigits@ IntegerDigits[n, 8]]]];  t

Formula

a(n) = A007094(A020137(n)).

A262154 Pseudoprimes to base 9, written in base 9.

Original entry on oeis.org

4, 8, 31, 57, 111, 144, 247, 347, 444, 627, 651, 754, 825, 854, 861, 1261, 1264, 1371, 1457, 1681, 1811, 2102, 2331, 2531, 3338, 3378, 3581, 3631, 3757, 3774, 4011, 4161, 4445, 4551, 5127, 6002, 6321, 6722, 7311, 7547, 8651, 10044, 10101, 10637, 11111, 11762, 12464, 12831, 12885, 13141, 13201, 15461, 16084, 16451
Offset: 1

Views

Author

Abdul Gaffar Khan, Sep 13 2015

Keywords

Links

Crossrefs

Cf. A007095 (numbers in base 9), A020138 (pseudoprimes to base 9).
Cf. A258189, A262101, A262102, A262103, A262104, A262105.

Programs

  • Mathematica
    base = 9; t = {}; n = 1;
While[Length[t] < 80, n++;
If[! PrimeQ[n] && PowerMod[base, n - 1, n] == 1,
  AppendTo[t, FromDigits@IntegerDigits[n, 9]]]]; t
  • PARI
    lista(nn, b=9) = {for (n=1, nn, if (Mod(b, n)^(n-1)==1 && !ispseudoprime(n) && n>1, print1(subst(Pol(digits(n,b), x), x, 10), ", ");););} \\ Michel Marcus, Sep 30 2015

Formula

a(n) = A007095(A020138(n)).
Showing 1-6 of 6 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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