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 11 results. Next

A353937 Smallest b > 1 such that b^(p-1) == 1 (mod p^4) for p = prime(n).

Original entry on oeis.org

17, 80, 182, 1047, 1963, 239, 4260, 2819, 19214, 2463, 15714, 51344, 20677, 3038, 224444, 189323, 11550, 397575, 201305, 15384, 840838, 1372873, 1576656, 278454, 1721322, 48072, 281007, 119551, 252595, 1001934, 3489507, 2489004, 598987, 3082551, 6136759, 3928984
Offset: 1

Views

Author

Felix Fröhlich, May 12 2022

Keywords

Crossrefs

Row k = 4 of A257833.
Cf. similar sequences for p^k: A039678 (k=2), A249275 (k=3), A353938 (k=5), A353939 (k=6), A353940 (k=7), A353941 (k=8), A353942 (k=9), A353943 (k=10).

Programs

  • Maple
    f:= proc(j) local p,b,i;
      p:= ithprime(j);
      b:= numtheory:-primroot(p^4) &^ (p^3) mod p^4;
      min(seq(b &^i mod p^4, i=1..p-2))
    end proc:
    f(1):= 17:
    map(f, [$1..40]); # Robert Israel, Dec 19 2024
  • Mathematica
    a[n_] := Module[{p = Prime[n], b = 2}, While[PowerMod[b, p - 1, p^4] != 1, b++]; b]; Array[a, 20] (* Amiram Eldar, May 12 2022 *)
  • PARI
    a(n) = my(p=prime(n)); for(b=2, oo, if(Mod(b, p^4)^(p-1)==1, return(b)))
    
  • Python
    from sympy import prime
    from sympy.ntheory.residue_ntheory import nthroot_mod
    def A353937(n): return 2**4+1 if n == 1 else int(nthroot_mod(1,(p:= prime(n))-1,p**4,True)[1]) # Chai Wah Wu, May 17 2022

A353938 Smallest b > 1 such that b^(p-1) == 1 (mod p^5) for p = prime(n).

Original entry on oeis.org

33, 242, 1068, 1353, 27216, 109193, 15541, 133140, 495081, 1115402, 2754849, 1353359, 649828, 3228564, 2359835, 4694824, 7044514, 28538377, 1111415, 77588426, 16178110, 2553319, 9571390, 158485540, 18664438, 146773512, 45639527, 448251412, 48834112, 141076650
Offset: 1

Views

Author

Felix Fröhlich, May 12 2022

Keywords

Crossrefs

Row k = 5 of A257833.
Cf. similar sequences for p^k: A039678 (k=2), A249275 (k=3), A353937 (k=4), A353939 (k=6), A353940 (k=7), A353941 (k=8), A353942 (k=9), A353943 (k=10).

Programs

  • Mathematica
    a[n_] := Module[{p = Prime[n], b = 2}, While[PowerMod[b, p - 1, p^5] != 1, b++]; b]; Array[a, 12] (* Amiram Eldar, May 12 2022 *)
  • PARI
    a(n) = my(p=prime(n)); for(b=2, oo, if(Mod(b, p^5)^(p-1)==1, return(b)))
    
  • Python
    from sympy import prime
    from sympy.ntheory.residue_ntheory import nthroot_mod
    def A353938(n): return 2**5+1 if n == 1 else int(nthroot_mod(1,(p:= prime(n))-1,p**5,True)[1]) # Chai Wah Wu, May 17 2022

A353939 Smallest b > 1 such that b^(p-1) == 1 (mod p^6) for p = prime(n).

Original entry on oeis.org

65, 728, 1068, 34967, 284995, 861642, 390112, 333257, 2818778, 42137700, 8078311, 33518159, 92331463, 21583010, 138173066, 8202731, 390421192, 1006953931, 77622331, 270657300, 5915704483, 522911165, 2507851273, 1329885769, 2789067613, 3987072867, 7938255646
Offset: 1

Views

Author

Felix Fröhlich, May 12 2022

Keywords

Crossrefs

Row k = 6 of A257833.
Cf. similar sequences for p^k: A039678 (k=2), A249275 (k=3), A353937 (k=4), A353938 (k=5), A353940 (k=7), A353941 (k=8), A353942 (k=9), A353943 (k=10).

Programs

  • Mathematica
    a[n_] := Module[{p = Prime[n], b = 2}, While[PowerMod[b, p - 1, p^6] != 1, b++]; b]; Array[a, 9] (* Amiram Eldar, May 12 2022 *)
  • PARI
    a(n) = my(p=prime(n)); for(b=2, oo, if(Mod(b, p^6)^(p-1)==1, return(b)))
    
  • Python
    from sympy import prime
    from sympy.ntheory.residue_ntheory import nthroot_mod
    def A353939(n): return 2**6+1 if n == 1 else int(nthroot_mod(1,(p:= prime(n))-1,p**6,True)[1]) # Chai Wah Wu, May 17 2022

Extensions

a(25)-a(27) from Jinyuan Wang, May 17 2022

A353940 Smallest b > 1 such that b^(p-1) == 1 (mod p^7) for p = prime(n).

Original entry on oeis.org

129, 2186, 32318, 82681, 758546, 6826318, 21444846, 44702922, 178042767, 393747520, 1548729003, 4741156070, 2203471139, 3242334565, 16609835418, 114175761515, 30338830655, 20115543070, 114457309347, 370162324382, 57877856575, 12692933349, 280646695286, 127762186531
Offset: 1

Views

Author

Felix Fröhlich, May 12 2022

Keywords

Crossrefs

Row k = 7 of A257833.
Cf. similar sequences for p^k: A039678 (k=2), A249275 (k=3), A353937 (k=4), A353938 (k=5), A353939 (k=6), A353941 (k=8), A353942 (k=9), A353943 (k=10).

Programs

  • PARI
    a(n) = my(p=prime(n)); for(b=2, oo, if(Mod(b, p^7)^(p-1)==1, return(b)))
    
  • Python
    from sympy import prime
    from sympy.ntheory.residue_ntheory import nthroot_mod
    def A353940(n): return 2**7+1 if n == 1 else int(nthroot_mod(1,(p:= prime(n))-1,p**7,True)[1]) # Chai Wah Wu, May 17 2022

Extensions

a(9)-a(11) from Amiram Eldar, May 12 2022
More terms from Jinyuan Wang, May 17 2022

A353941 Smallest b > 1 such that b^(p-1) == 1 (mod p^8) for p = prime(n).

Original entry on oeis.org

257, 6560, 110443, 2387947, 9236508, 6826318, 112184244, 674273372, 571782680, 8827420195, 46142113101, 85760131222, 287369842623, 120773832179, 83209719751, 1684374218587, 6358345589299, 6305601215112, 5800992744105, 33960226045484, 56924554232879, 11856046381401
Offset: 1

Views

Author

Felix Fröhlich, May 12 2022

Keywords

Crossrefs

Row k = 8 of A257833.
Cf. similar sequences for p^k: A039678 (k=2), A249275 (k=3), A353937 (k=4), A353938 (k=5), A353939 (k=6), A353940 (k=7), A353942 (k=9), A353943 (k=10).

Programs

  • PARI
    a(n) = my(p=prime(n)); for(b=2, oo, if(Mod(b, p^8)^(p-1)==1, return(b)))
    
  • Python
    from sympy import prime
    from sympy.ntheory.residue_ntheory import nthroot_mod
    def A353941(n): return 2**8+1 if n == 1 else int(nthroot_mod(1,(p:= prime(n))-1,p**8,True)[1]) # Chai Wah Wu, May 17 2022

Extensions

a(7)-a(8) from Amiram Eldar, May 12 2022
More terms from Jinyuan Wang, May 17 2022

A353942 Smallest b > 1 such that b^(p-1) == 1 (mod p^9) for p = prime(n).

Original entry on oeis.org

513, 19682, 280182, 14906455, 676386984, 822557039, 8185328614, 1835323405, 147534349327, 430099398783, 746688111476, 3054750102760, 9430469115218, 42562034654367, 92084372092298, 28307243117603, 17362132628379, 430275700643181, 478910674129864, 69114209866295
Offset: 1

Views

Author

Felix Fröhlich, May 12 2022

Keywords

Crossrefs

Row k = 9 of A257833.
Cf. similar sequences for p^k: A039678 (k=2), A249275 (k=3), A353937 (k=4), A353938 (k=5), A353939 (k=6), A353940 (k=7), A353941 (k=8), A353943 (k=10).

Programs

  • PARI
    a(n) = my(p=prime(n)); for(b=2, oo, if(Mod(b, p^9)^(p-1)==1, return(b)))
    
  • Python
    from sympy import prime
    from sympy.ntheory.residue_ntheory import nthroot_mod
    def A353942(n): return 2**9+1 if n == 1 else int(nthroot_mod(1,(p:= prime(n))-1,p**9,True)[1]) # Chai Wah Wu, May 17 2022

Extensions

a(5)-a(6) from Amiram Eldar, May 12 2022
More terms from Jinyuan Wang, May 17 2022

A353943 Smallest b > 1 such that b^(p-1) == 1 (mod p^10) for p = prime(n).

Original entry on oeis.org

1025, 59048, 3626068, 135967276, 1509748675, 14149342837, 109522148350, 649340249056, 191730243526, 45941644105613, 6359301533362, 24287026146320, 265934493600922, 927939012431924, 1377672497815095, 4440230734662684, 10400007512898615, 12198961352308417
Offset: 1

Views

Author

Felix Fröhlich, May 12 2022

Keywords

Crossrefs

Row k = 10 of A257833.
Cf. similar sequences for p^k: A039678 (k=2), A249275 (k=3), A353937 (k=4), A353938 (k=5), A353939 (k=6), A353940 (k=7), A353941 (k=8), A353942 (k=9).

Programs

  • PARI
    a(n) = my(p=prime(n)); for(b=2, oo, if(Mod(b, p^10)^(p-1)==1, return(b)))
    
  • Python
    from sympy.ntheory.residue_ntheory import nthroot_mod
    from sympy import prime
    def A353943(n): return 2**10+1 if n == 1 else int(nthroot_mod(1,(p:= prime(n))-1,p**10,True)[1]) # Chai Wah Wu, May 17 2022

Extensions

a(5)-a(6) from Amiram Eldar, May 12 2022
More terms from Jinyuan Wang, May 17 2022

A258045 Table T(b, m) of largest exponents k such that for p = prime(m) and base b > 1 the congruence b^(p-1) == 1 (mod p^k) is satisfied, or 0 if no such k exists, read by antidiagonals (downwards).

Original entry on oeis.org

0, 1, 1, 1, 0, 0, 1, 1, 1, 2, 1, 1, 1, 1, 0, 1, 2, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 2, 2, 3, 1, 1, 1, 1, 1, 0, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 0, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1
Offset: 2

Views

Author

Felix Fröhlich, May 26 2015

Keywords

Comments

a(n) > 1 if b appears in row k, column n of the table in A257833 for k > 1 and n > 1.

Examples

			T(3, 5) = 2, because the largest Wieferich exponent of prime(5) = 11 in base 3 is 2.
Table starts
b=2:  0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 ...
b=3:  1, 0, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1 ...
b=4:  0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 ...
b=5:  2, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 ...
b=6:  0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 ...
b=7:  1, 1, 2, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 ...
b=8:  0, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 ...
b=9:  3, 0, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1 ...
b=10: 0, 2, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 ...
b=11: 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1 ...
b=12: 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 ...
b=13: 2, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1 ...
b=14: 0, 1, 1, 0, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1 ...
b=15: 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 ...
b=16: 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 ...
b=17: 4, 2, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1 ...
b=18: 0, 0, 2, 3, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1 ...
b=19: 1, 2, 1, 3, 1, 2, 1, 0, 1, 1, 1, 1, 1, 2 ...
b=20: 0, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 ...
....
The triangle a(n ,m) begins:
  m 1 2 3 4 5 6 7 8 9 10 11 ...
n
2   0
3   1 1
4   1 0 0
5   1 1 1 2
6   1 1 1 1 0
7   1 2 1 0 0 1
8   1 1 1 1 1 1 0
9   1 1 1 1 1 2 2 3
10  1 1 1 1 1 0 1 0 0
11  1 1 1 1 1 1 1 1 2  1
12  1 1 1 1 1 1 1 1 0  1  0
...
		

Crossrefs

Programs

  • PARI
    for(b=2, 20, forprime(p=1, 70, k=0; while(Mod(b, p^k)^(p-1)==1, k++); if(k > 0, k--); print1(k, ", ")); print(""))

Formula

a(n, m) = T(m+1, n-m), n >=2, m = 1, 2, ..., n-1. - Wolfdieter Lang, Jun 29 2015

Extensions

Edited by Wolfdieter Lang, Jun 29 2015

A273433 Smallest base b > 1 such that p = prime(n) satisfies b^(p-1) == 1 (mod p^n).

Original entry on oeis.org

3, 8, 57, 1047, 27216, 861642, 21444846, 674273372, 147534349327, 45941644105613, 244158265828023, 569209871196597077, 15204969799577672558, 2111244131216208612515, 129192323492968413250921, 25814874251189658671192458, 13543096262710710570994132579
Offset: 1

Views

Author

Felix Fröhlich, May 22 2016

Keywords

Crossrefs

Cf. A257833.

Programs

  • PARI
    a(n) = my(p=prime(n), b=2); while(Mod(b, p^n)^(p-1)!=1, b++); b

Formula

a(n) = A257833(n, n) for n > 1.

Extensions

a(9)-a(17) from Hiroaki Yamanouchi, May 26 2016

A281747 Smallest b > 1 such that p = prime(n) satisfies b^(p-1) == 1 (mod p^p).

Original entry on oeis.org

5, 26, 1068, 82681, 5392282366, 11356596271444, 34451905517028761171, 340625514346676110671584, 308318432223607315018221180590, 8566187045843934976180705488213013173127, 1099862052702774330481800364074681495062836757, 8170421001593885871548404108552563632485969048059688187
Offset: 1

Views

Author

Felix Fröhlich, Jan 29 2017

Keywords

Comments

a(n) is the element in row prime(n), column n of the table in A257833.
Is the sequence always nondecreasing, or stronger, is it always increasing?
For odd primes p, if c is a primitive root mod p^p then b == c^(p^(p-1)) (mod p^p) satisfies this. Thus a(n) < prime(n)^prime(n) for n > 1. - Robert Israel, Jan 30 2017

Crossrefs

Cf. A257833.

Programs

  • Maple
    f:= proc(p) local c,j;
           c:= numtheory:-primroot(p^p);
           min(seq(c &^ (j*p^(p-1)) mod p^p, j=1..p-2))
    end proc:
    5, seq(f(ithprime(i)),i=2..15); # Robert Israel, Jan 30 2017
  • Mathematica
    Table[b = 2; While[PowerMod[b, (# - 1), #^#] &@ Prime@ n != 1, b++]; b, {n, 4}] (* Michael De Vlieger, Jan 30 2017 *)
  • PARI
    a(n) = my(p=prime(n), b=2); while(Mod(b, p^p)^(p-1)!=1, b++); b

Extensions

More terms from Robert Israel, Jan 30 2017
Showing 1-10 of 11 results. Next