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 1-9 of 9 results.

A025020 Numbers whose least quadratic nonresidue (A020649) is 2.

Original entry on oeis.org

3, 4, 5, 6, 8, 9, 10, 11, 12, 13, 15, 16, 18, 19, 20, 21, 22, 24, 25, 26, 27, 28, 29, 30, 32, 33, 35, 36, 37, 38, 39, 40, 42, 43, 44, 45, 48, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 63, 64, 65, 66, 67, 68, 69, 70, 72, 74, 75, 76, 77, 78, 80, 81, 83, 84, 85, 86, 87, 88, 90, 91, 92
Offset: 1

Views

Author

David W. Wilson

Keywords

Links

Crossrefs

Cf. A020649, A025021, A025022, A025023, A025024, A025025, A025026, A025027, A025028, A025029.

Programs

  • Mathematica
    Select[Range[100], Min @ Complement[Range[# - 1], Mod[Range[#/2]^2, #]] == 2 &] (* Amiram Eldar, Oct 31 2020 *)
  • PARI
    isA025020(n)={local(r);r=1;for(m=1,n-1,if(m^2%n==2,r=0));r} \\ Michael B. Porter, Apr 16 2010

A025021 Numbers whose least quadratic nonresidue (A020649) is 3.

Original entry on oeis.org

7, 14, 17, 31, 34, 41, 49, 62, 79, 82, 89, 98, 103, 113, 119, 127, 137, 151, 158, 161, 178, 199, 206, 217, 223, 226, 233, 238, 254, 257, 271, 274, 281, 287, 289, 302, 322, 329, 343, 353, 367, 391, 398, 401, 434, 439, 446, 449, 463, 466, 487, 497, 511, 514, 521, 527, 542
Offset: 1

Views

Author

David W. Wilson

Keywords

Comments

n such that n is not divisible by 4, all primes dividing n are in A038873, and at least one prime dividing n is in A003630. - Robert Israel, Jul 19 2017

Links

Crossrefs

Cf. A020649, A025020, A025022, A025023, A025024, A025025, A025026, A025027, A025028, A025029.
Cf. A003630, A038873.

Programs

  • Maple
    select(t -> numtheory:-quadres(2,t) = 1 and numtheory:-quadres(3,t)=-1, [$1..1000]); # Robert Israel, Jul 19 2017
  • Mathematica
    Select[Range[500], Min @ Complement[Range[# - 1], Mod[Range[#/2]^2, #]] == 3 &] (* Amiram Eldar, Oct 31 2020 *)
  • PARI
    residue(n,m)={local(r);r=0;for(i=1,floor(m/2),if(i^2%m==n,r=1));r}
isA025021(n)=residue(2,n) && !residue(3,n) \\ Michael B. Porter, Apr 18 2010

A025022 Numbers whose least quadratic nonresidue (A020649) is 5.

Original entry on oeis.org

23, 46, 47, 73, 94, 97, 146, 167, 193, 194, 263, 313, 334, 337, 383, 386, 433, 457, 503, 526, 529, 577, 626, 647, 673, 674, 743, 766, 863, 866, 887, 914, 937, 983, 1006, 1033, 1058, 1081, 1103, 1153, 1154, 1223, 1294, 1297, 1346, 1367, 1486, 1487, 1583, 1607
Offset: 1

Views

Author

David W. Wilson

Keywords

Links

Crossrefs

Cf. A020649, A025020, A025021, A025023, A025024, A025025, A025026, A025027, A025028, A025029.

Programs

  • Mathematica
    Select[Range[1600], Min @ Complement[Range[# - 1], Mod[Range[#/2]^2, #]] == 5 &] (* Amiram Eldar, Oct 31 2020 *)
  • PARI
    residue(n,m)={local(r);r=0;for(i=1,floor(m/2),if(i^2%m==n,r=1));r}
isA025022(n)=residue(2,n) && residue(3,n) && !residue(5,n) \\ Michael B. Porter, Apr 18 2010

A025023 Numbers whose least quadratic nonresidue (A020649) is 7.

Original entry on oeis.org

71, 142, 191, 239, 241, 359, 382, 409, 431, 478, 482, 599, 601, 718, 769, 818, 862, 911, 1031, 1198, 1202, 1249, 1321, 1439, 1489, 1538, 1609, 1822, 1871, 2039, 2062, 2089, 2111, 2161, 2281, 2498, 2591, 2642, 2711, 2878, 2879, 2978, 3001, 3119, 3121, 3169
Offset: 1

Views

Author

David W. Wilson

Keywords

Links

Crossrefs

Cf. A020649, A025020, A025021, A025022, A025024, A025025, A025026, A025027, A025028, A025029.

Programs

  • Mathematica
    Select[Range[3200], Min @ Complement[Range[# - 1], Mod[Range[#/2]^2, #]] == 7 &] (* Amiram Eldar, Oct 31 2020 *)
  • PARI
    residue(n,m)=local(r);r=0;for(i=1,floor(m/2),if(i^2%m==n,r=1));r
isA025023(n)=residue(2,n) && residue(3,n) && residue(5,n) && !residue(7,n) \\ Michael B. Porter, Apr 19 2010
  • PARI
    is(n)=issquare(Mod(2,n)) && issquare(Mod(3,n)) && issquare(Mod(5,n)) && !issquare(Mod(7,n)) \\ Charles R Greathouse IV, Jan 24 2020

A025024 Numbers whose least quadratic nonresidue (A020649) is 11.

Original entry on oeis.org

311, 622, 719, 839, 1009, 1129, 1201, 1438, 1511, 1678, 1801, 2018, 2258, 2399, 2402, 2521, 3022, 3049, 3191, 3359, 3361, 3602, 3889, 4079, 4201, 4561, 4679, 4729, 4798, 4871, 5039, 5042, 5209, 5351, 5591, 5879, 5881, 6098, 6359, 6382, 6718, 6719, 6722
Offset: 1

Views

Author

David W. Wilson

Keywords

Links

Crossrefs

Cf. A020649, A025020, A025021, A025022, A025023, A025025, A025026, A025027, A025028, A025029.

Programs

  • Mathematica
    Select[Range[7000], Min @ Complement[Range[# - 1], Mod[Range[#/2]^2, #]] == 11 &] (* Amiram Eldar, Oct 31 2020 *)
  • PARI
    residue(n,m)=local(r);r=0;for(i=1,floor(m/2),if(i^2%m==n,r=1));r
isA025024(n)=local(a);a=1;forprime(p=2,7,a=a && residue(p,n));a=a && !residue(11,n);a \\ Michael B. Porter, Apr 30 2010
  • PARI
    is(n)=issquare(Mod(2,n)) && issquare(Mod(3,n)) && issquare(Mod(5,n)) && issquare(Mod(7,n)) && !issquare(Mod(11,n)) \\ Charles R Greathouse IV, Jan 24 2020

A025025 Numbers whose least quadratic nonresidue (A020649) is 13.

Original entry on oeis.org

479, 958, 1151, 1319, 2302, 2351, 2638, 2689, 3529, 3671, 3911, 4702, 4751, 4919, 5378, 5519, 5569, 6599, 7058, 7342, 7559, 7561, 7681, 7822, 8951, 9241, 9502, 9601, 9719, 9769, 9838, 11038, 11138, 12049, 12239, 12721, 12911, 13151, 13198, 14159
Offset: 1

Views

Author

David W. Wilson

Keywords

Links

Crossrefs

Cf. A020649, A025020, A025021, A025022, A025023, A025024, A025026, A025027, A025028, A025029.

Programs

  • Mathematica
    Select[Range[14000], Min @ Complement[Range[# - 1], Mod[Range[#/2]^2, #]] == 13 &] (* Amiram Eldar, Oct 31 2020 *)
  • PARI
    residue(n,m)=local(r);r=0;for(i=1,floor(m/2),if(i^2%m==n,r=1));r
isA025025(n)=local(a);a=1;forprime(p=2,11,a=a && residue(p,n));a=a && !residue(13,n);a \\ Michael B. Porter, Apr 30 2010
  • PARI
    is(n)=issquare(Mod(2,n)) && issquare(Mod(3,n)) && issquare(Mod(5,n)) && issquare(Mod(7,n)) && issquare(Mod(11,n)) && !issquare(Mod(13,n)) \\ Charles R Greathouse IV, Jan 24 2020

A025027 Numbers whose least quadratic nonresidue (A020649) is 19.

Original entry on oeis.org

5711, 9239, 10391, 10799, 11422, 14951, 18478, 20782, 21598, 29902, 33049, 34319, 36599, 37489, 40031, 42719, 44641, 49009, 49921, 51769, 53089, 55441, 57119, 59929, 61151, 61871, 63361, 66098, 67369, 67679, 68638, 69001, 71569, 73198, 74978, 75479
Offset: 1

Views

Author

David W. Wilson

Keywords

Links

Crossrefs

Cf. A020649, A025020, A025021, A025022, A025023, A025024, A025025, A025026, A025028, A025029.

Programs

  • Mathematica
    Select[Range[20000], Min @ Complement[Range[# - 1], Mod[Range[#/2]^2, #]] == 19 &] (* Amiram Eldar, Oct 31 2020 *)
  • PARI
    residue(n,m)=local(r);r=0;for(i=1,floor(m/2),if(i^2%m==n,r=1));r
isA025027(n)=local(a);a=1;forprime(p=2,17,a=a && residue(p,n));a=a && !residue(19,n);a \\ Michael B. Porter, Apr 30 2010
  • PARI
    is(n)=forprime(p=2,19, if(!issquare(Mod(p,n)), return(p==19))); 0 \\ Charles R Greathouse IV, Jan 24 2020

A025028 Numbers whose least quadratic nonresidue (A020649) is 23.

Original entry on oeis.org

10559, 15791, 21118, 31582, 50951, 53231, 53881, 88079, 88919, 92569, 97919, 101902, 102001, 106462, 107762, 123191, 128519, 130729, 138311, 142271, 144169, 158759, 166319, 166609, 167879, 173209, 174599, 176158, 176401, 177838, 185138
Offset: 1

Views

Author

David W. Wilson

Keywords

Links

Crossrefs

Cf. A020649, A025020, A025021, A025022, A025023, A025024, A025025, A025026, A025027, A025029.

Programs

  • PARI
    residue(n,m)=local(r);r=0;for(i=1,floor(m/2),if(i^2%m==n,r=1));r
isA025028(n)=local(a);a=1;forprime(p=2,19,a=a && residue(p,n));a=a && !residue(23,n);a \\ Michael B. Porter, Apr 30 2010
  • PARI
    is(n)=forprime(p=2,23, if(!issquare(Mod(p,n)), return(p==23))); 0 \\ Charles R Greathouse IV, Jan 24 2020

A025029 Numbers whose least quadratic nonresidue (A020649) is 29.

Original entry on oeis.org

18191, 35279, 36382, 38639, 63839, 70558, 77278, 87481, 95471, 104711, 127678, 147671, 174962, 185641, 190942, 193751, 199559, 209422, 217439, 284231, 290351, 295342, 312311, 322559, 336361, 363359, 371282, 375359, 387502, 394969, 399118
Offset: 1

Views

Author

David W. Wilson

Keywords

Links

Crossrefs

Cf. A020649, A025020, A025021, A025022, A025023, A025024, A025025, A025026, A025027, A025028.

Programs

  • PARI
    residue(n,m)=local(r);r=0;for(i=0,floor(m/2),if(i^2%m==n,r=1));r
isA025029(n)=local(a);a=1;forprime(p=2,23,a=a && residue(p,n));a=a && !residue(29,n);a \\ Michael B. Porter, May 06 2010
  • PARI
    is(n)=forprime(p=2,29, if(!issquare(Mod(p,n)), return(p==29))); 0 \\ Charles R Greathouse IV, Jan 24 2020
Showing 1-9 of 9 results.

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