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 1-10 of 17 results. Next

A090084 Even pseudoprimes to base 11.

Original entry on oeis.org

10, 70, 190, 1330, 8170, 9730, 24130, 28462, 58030, 98458, 143830, 144886, 327370, 856786, 1580230, 1620130, 3536470, 5274970, 6082490, 6376126, 6792710, 8066170, 8610610, 14076910, 17728930, 27275158, 42447406, 52970386, 53497978, 68925130
Offset: 1

Views

Author

Labos Elemer, Nov 25 2003

Keywords

Links

Crossrefs

Cf. A020139.
Cf. A006935, A130433, A090082, A090083, A090085, A130434, A130435, A130436, A130438, A130439, A130440, A130441, A130442, A130443.

Programs

  • Mathematica
    Do[ f=PowerMod[ 11, 2n-1, 2n ]; If[ f==1, Print[ 2n ] ],{n,2,800000} ] (* Alexander Adamchuk, May 26 2007 *)
lst = {}; Do[ If[ PowerMod[11, 2n - 1, 2n] == 1, AppendTo[lst, 2n]], {n, 2, 2*10^9}]; lst (* Robert G. Wilson v, Jun 01 2007 *)
Select[Range[4,68926000,2],PowerMod[11,#-1,#]==1&] (* Harvey P. Dale, Oct 16 2021 *)
  • PARI
    is(k) = k > 2 && !(k % 2) &&  Mod(11, k)^(k-1) == 1; \\ Amiram Eldar, Sep 18 2024

Extensions

More terms from Alexander Adamchuk, May 26 2007
Further terms from Robert G. Wilson v, Jun 01 2007

A130434 Even pseudoprimes to base 7.

Original entry on oeis.org

6, 16806, 29234, 67798, 791578, 1234806, 1807566, 2427706, 12562534, 29147626, 29783134, 38357866, 41716918, 50167486, 99392626, 111664666, 162474586, 169707826, 281780346, 286351066, 349880326, 423200566, 463054594, 479581642
Offset: 1

Views

Author

Alexander Adamchuk, May 26 2007

Keywords

Links

Crossrefs

Cf. A005938, A006935, A130433, A090082, A090083, A090084, A090085, A130435, A130436, A130437, A130438, A130439, A130440, A130441, A130442, A130443.

Programs

  • Mathematica
    lst = {}; Do[ If[ PowerMod[7, 2n - 1, 2n] == 1, AppendTo[lst, 2n]; Print[2n]], {n, 2, 24000000}]; lst (* Robert G. Wilson v, May 28 2007 *)

Extensions

a(9)-a(37) from Robert G. Wilson v, May 28 2007

A130435 Even pseudoprimes to base 13.

Original entry on oeis.org

4, 6, 12, 244, 276, 2806, 5028, 10308, 40132, 51118, 115644, 185646, 216492, 237084, 789636, 936046, 941818, 1062876, 1237276, 1469716, 2119002, 2201002, 2410354, 2446426, 3198196, 4319052, 4979316, 5329468, 5496492, 7171876, 9513076
Offset: 1

Views

Author

Alexander Adamchuk, May 26 2007

Keywords

Links

Crossrefs

Cf. A020141, A006935, A130433, A090082, A090083, A090084, A090085, A130434, A130436, A130437, A130438, A130439, A130440, A130441, A130442, A130443.

Programs

  • Mathematica
    Do[ f=PowerMod[ 13, 2n-1, 2n ]; If[ f==1, Print[ 2n ] ], {n,2,1000000} ] (* Robert G. Wilson v, May 31 2007 *)
  • PARI
    is(k) = k > 2 && !(k % 2) &&  Mod(13, k)^(k-1) == 1; \\ Amiram Eldar, Sep 18 2024

Extensions

a(26)-a(31) from Robert G. Wilson v, May 31 2007

A130436 Even pseudoprimes to base 17.

Original entry on oeis.org

4, 8, 16, 1228, 4912, 5662, 11476, 76798, 168904, 387676, 938792, 1003276, 1147576, 1415044, 1419856, 1832836, 2297296, 3976624, 5470126, 6376126, 7309576, 9649624, 12423676, 13193776, 14026888, 14652496, 19136272, 20570936, 24604696
Offset: 1

Views

Author

Alexander Adamchuk, May 26 2007

Keywords

Links

Crossrefs

Cf. A020145, A006935, A130433, A090082, A090083, A090084, A090085, A130434, A130435, A130437, A130438, A130439, A130440, A130441, A130442, A130443.

Programs

  • Mathematica
    lst = {}; Do[ If[ PowerMod[17, 2n - 1, 2n] == 1, AppendTo[lst, 2n]], {n, 2, 2*10^9}]; lst (* Robert G. Wilson v, Jun 01 2007 *)
  • PARI
    is(k) = k > 2 && !(k % 2) &&  Mod(17, k)^(k-1) == 1; \\ Amiram Eldar, Sep 18 2024

Extensions

a(13)-a(29) from Robert G. Wilson v, Jun 01 2007

A130438 Even pseudoprimes to base 23.

Original entry on oeis.org

22, 154, 638, 946, 1738, 2926, 12166, 15862, 33022, 125686, 248218, 285286, 358534, 596926, 697334, 1007566, 3426346, 3675826, 3755158, 4147522, 6518974, 19866946, 26336926, 34220746, 35083426, 46365814, 54148654, 54342046, 72789466
Offset: 1

Views

Author

Alexander Adamchuk, May 26 2007

Keywords

Links

Crossrefs

Cf. A020151, A006935, A130433, A090082, A090083, A090084, A090085, A130434, A130435, A130436, A130437, A130439, A130440, A130441, A130442, A130443.

Programs

  • Mathematica
    lst = {}; Do[ If[ PowerMod[17, 2n - 1, 2n] == 1, AppendTo[lst, 2n]], {n, 2, 2*10^9}]; lst (* Robert G. Wilson v, Jun 01 2007 *)
  • PARI
    is(k) = k > 2 && !(k % 2) &&  Mod(23, k)^(k-1) == 1; \\ Amiram Eldar, Sep 29 2024

Extensions

More terms from Robert G. Wilson v, Jun 01 2007

A130439 Even pseudoprimes to base 29.

Original entry on oeis.org

4, 14, 28, 52, 268, 364, 1876, 3484, 5356, 7294, 24388, 66788, 283276, 286492, 339556, 404236, 860692, 1153684, 1381132, 1478764, 1696708, 2073722, 2182726, 2222122, 4922164, 7790146, 8200036, 9679138, 10881052, 14863516, 15476266
Offset: 1

Views

Author

Alexander Adamchuk, May 26 2007

Keywords

Links

Crossrefs

Cf. A020157, A006935, A130433, A090082, A090083, A090084, A090085, A130434, A130435, A130436, A130437, A130438, A130440, A130441, A130442, A130443.

Programs

  • Mathematica
    Do[ f=PowerMod[ 29, 2n-1, 2n ]; If[ f==1, Print[ 2n ] ], {n,2,500000} ]
lst = {}; Do[ If[ PowerMod[17, 2n - 1, 2n] == 1, AppendTo[lst, 2n]], {n, 2, 2^31}]; lst (* Robert G. Wilson v, Jun 01 2007 *)
  • PARI
    is(k) = k > 2 && !(k % 2) &&  Mod(29, k)^(k-1) == 1; \\ Amiram Eldar, Sep 29 2024

Extensions

More terms from Robert G. Wilson v, Jun 01 2007

A130440 Even pseudoprimes to base 31.

Original entry on oeis.org

6, 10, 30, 66, 946, 3310, 10470, 36370, 60126, 104106, 128766, 170710, 323670, 369370, 398266, 596926, 813430, 1145166, 1494690, 2384866, 5960746, 6376126, 8178346, 18327310, 31380922, 34102630, 37105762, 40796526, 41950966, 41983446
Offset: 1

Views

Author

Alexander Adamchuk, May 26 2007

Keywords

Links

Crossrefs

Cf. A020159, A006935, A130433, A090082, A090083, A090084, A090085, A130434, A130435, A130436, A130437, A130438, A130439, A130441, A130442, A130443.

Programs

  • Mathematica
    Do[ f=PowerMod[ 31, 2n-1, 2n ]; If[ f==1, Print[ 2n ] ], {n,2,500000} ]
lst = {}; Do[ If[ PowerMod[31, 2n - 1, 2n] == 1, AppendTo[lst, 2n]], {n, 2, 2^31}]; lst (* Robert G. Wilson v, Jun 01 2007 *)
  • PARI
    is(k) = k > 2 && !(k % 2) &&  Mod(31, k)^(k-1) == 1; \\ Amiram Eldar, Sep 29 2024

Extensions

More terms from Robert G. Wilson v, Jun 01 2007

A130442 Even pseudoprimes to base 41.

Original entry on oeis.org

4, 8, 10, 20, 40, 344, 4870, 6892, 17230, 68920, 250820, 296440, 317032, 368722, 369370, 451426, 472312, 473240, 632270, 2326472, 3186730, 3429190, 4438760, 4670956, 4948456, 5509540, 8990356, 11817604, 11841436, 13094342, 17668360
Offset: 1

Views

Author

Alexander Adamchuk, May 26 2007

Keywords

Links

Crossrefs

Cf. A020169 (pseudoprimes to base 41).
Cf. A006935 (even pseudoprimes (or primes) to base 2: n divides 2^n - 2, n even).
Cf. A130433 (even pseudoprimes to base 3).
Cf. A090082 (even pseudoprimes to base 5).
Cf. A090083, A090084, A090085.
Cf. A130434, A130435, A130436, A130437, A130438, A130439, A130440, A130441, A130443.
Cf. A020169, A006935, A130433, A090082, A090083, A090084, A090085, A130434, A130435, A130436, A130437, A130438, A130439, A130440, A130441, A130443.

Programs

  • Mathematica
    Do[ f=PowerMod[ 41, 2n-1, 2n ]; If[ f==1, Print[ 2n ] ], {n,2,500000} ]
lst = {}; Do[ If[ PowerMod[41, 2n - 1, 2n] == 1, AppendTo[lst, 2n]], {n, 2, 2^31}]; lst (* Robert G. Wilson v, Jun 01 2007 *)
  • PARI
    is(k) = k > 2 && !(k % 2) &&  Mod(41, k)^(k-1) == 1; \\ Amiram Eldar, Sep 29 2024

Extensions

More terms from Robert G. Wilson v, Jun 01 2007

A130443 Even pseudoprimes to base 43.

Original entry on oeis.org

6, 14, 42, 526974, 9157582, 21001206, 49419154, 156418318, 157058362, 223741702, 467016562, 531330346, 601692022, 681377698, 888739174, 931053466, 1037629198, 1390950926, 1392718618, 2175608494, 2377982166, 3045063946, 5136468646
Offset: 1

Views

Author

Alexander Adamchuk, May 26 2007, Jun 20 2007

Keywords

Links

Crossrefs

Cf. A020171, A006935, A130433, A090082, A090083, A090084, A090085, A130434, A130435, A130436, A130437, A130438, A130439, A130440, A130441, A130442.

Programs

  • Mathematica
    lst = {}; Do[ If[ PowerMod[43, 2n - 1, 2n] == 1, AppendTo[lst, 2n]], {n, 2, 1800000000}]; lst (* Robert G. Wilson v, Jun 01 2007 *)
  • PARI
    is(k) = k > 2 && !(k % 2) &&  Mod(43, k)^(k-1) == 1; \\ Amiram Eldar, Sep 29 2024

Extensions

More terms from Robert G. Wilson v, Jun 01 2007

A090083 Even pseudoprimes to base 9.

Original entry on oeis.org

4, 8, 28, 52, 286, 364, 532, 616, 946, 1036, 1288, 2806, 2926, 3052, 4376, 4636, 5356, 6364, 8744, 8866, 11476, 12124, 15964, 17446, 19096, 19684, 21196, 21736, 24046, 24388, 26596, 31876
Offset: 1

Views

Author

Labos Elemer, Nov 25 2003

Keywords

Links

Crossrefs

Cf. A020138.
Cf. A006935, A130433, A090082, A090084, A090085, A130434, A130435, A130436, A130438, A130439, A130440, A130441, A130442, A130443.

Programs

  • Mathematica
    Do[s=Mod[ -1+9^(n-1), n]; If[Equal[s, 0]&&!PrimeQ[n]&&EvenQ[n], Print[n]], {n, 1, 1000000}]
  • PARI
    is(n)=Mod(9, n)^(n-1)==1&&!isprime(n)&&n%2==0 \\ Charles R Greathouse IV, Apr 12 2012
  • PARI
    p=2; forprime(q=3, 1e8, forstep(n=p+1, q-1, 2, if(Mod(9, n)^(n-1)==1, print1(n", "))); p=q) \\ Charles R Greathouse IV, Apr 12 2012
Showing 1-10 of 17 results. Next

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