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.

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A224322 Primes without "9" as a digit that remain prime when any single digit is replaced with "9".

Original entry on oeis.org

17, 107, 137, 347, 1013, 1433, 1613, 3767, 4337, 8623, 25633, 31114073
Offset: 1

Views

Author

Arkadiusz Wesolowski, Apr 03 2013

Keywords

Comments

No more terms < 10^13.

Crossrefs

Cf. A224319-A224321. Subsequence of A038617.

Programs

  • Mathematica
    lst = {}; n = 9; Do[If[PrimeQ[p], i = IntegerDigits[p]; If[FreeQ[i, n], t = 0; s = IntegerLength[p]; Do[If[PrimeQ@FromDigits@Insert[Drop[i, {d}], n, d], t++, Break[]], {d, s}]; If[t == s, AppendTo[lst, p]]]], {p, 25633}]; lst
    pr9Q[n_]:=Module[{idn=IntegerDigits[n]},FreeQ[idn,9]&&AllTrue[Table[ FromDigits[ ReplacePart[ idn,i->9]],{i,Length[idn]}],PrimeQ]]; Select[ Prime[Range[2*10^6]],pr9Q] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Mar 30 2015 *)

A254315 Number of distinct digits in the prime factorization of n (counting terms of the form p^1 as p).

Original entry on oeis.org

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

Views

Author

Michel Lagneau, Jan 28 2015

Keywords

Comments

Write n as product of primes raised to powers; then a(n) is the total number of distinct digits in product representation (number of distinct digits in all the primes and number of distinct digits in all the exponents that are greater than 1).
a(n)<=10. The least n such that a(n)=10 is n = 41701690 = 2*5*47*83*1069.
Property: a(p) = A043537(p), for p prime.
From Michel Marcus, Feb 21 2015: (Start)
For p in A038604, a(p^2) = A043537(p) + 1.
For p in A038611, a(p^3) = A043537(p) + 1.
For p in A038612, a(p^4) = A043537(p) + 1.
For p in A038613, a(p^5) = A043537(p) + 1.
For p in A038614, a(p^6) = A043537(p) + 1.
For p in A038615, a(p^7) = A043537(p) + 1.
For p in A038616, a(p^8) = A043537(p) + 1.
For p in A038617, a(p^9) = A043537(p) + 1.
(End)

Examples

			a(36)=2 because 36 = 2^2 * 3^2 => 2 distinct digits.
a(414)=2 because 414 = 2 * 3^2 * 23 => 2 distinct digits.
		

Crossrefs

Programs

  • Maple
    with(ListTools):
    nn:=100:
      for n from 2 to nn do:
        n0:=length(n):lst:={}:x0:=ifactors(n):
        y:=Flatten(x0[2]):z:=convert(y,set):
        z1:=z minus {1}:nn0:=nops(z1):
         for k from 1 to nn0 do :
          t1:=convert(z1[k],base,10):z2:=convert(t1,set):
          lst:=lst union z2:
         od:
         nn1:=nops(lst):printf(`%d, `,nn1):
         od :
  • Mathematica
    f[n_] := Block[{pf = FactorInteger@ n, i}, Length@ DeleteDuplicates@ Flatten@ IntegerDigits@ Rest@ Flatten@ Reap@ Do[If[Last[pf[[i]]] == 1, Sow@ First@ pf[[i]], Sow@ FromDigits@ Flatten[IntegerDigits /@ pf[[i]]]], {i, Length@ pf}]]; Array[f,100] (* Michael De Vlieger, Jan 29 2015 *)
  • PARI
    print1(1,", ");for(k=2,100,s=[];F=factor(k);for(i=1,#F[,1],s=concat(s,digits(F[i,1]));if(F[i,2]>1,s=concat(s,digits(F[i,2]))));print1(#vecsort(s,,8),", ")) \\ Derek Orr, Jan 30 2015
    
  • Python
    from sympy import factorint
    def A254315(n):
        return len(set([x for l in [[d for d in str(p)]+[d for d in str(e) if d != '1'] for p,e in factorint(n).items()] for x in l]))
    # Chai Wah Wu, Feb 24 2015

A386358 Primes without {7, 9} as digits.

Original entry on oeis.org

2, 3, 5, 11, 13, 23, 31, 41, 43, 53, 61, 83, 101, 103, 113, 131, 151, 163, 181, 211, 223, 233, 241, 251, 263, 281, 283, 311, 313, 331, 353, 383, 401, 421, 431, 433, 443, 461, 463, 503, 521, 523, 541, 563, 601, 613, 631, 641, 643, 653, 661, 683, 811, 821, 823
Offset: 1

Views

Author

Jason Bard, Jul 20 2025

Keywords

Crossrefs

Intersection of A038615 and A038617.

Programs

  • Magma
    [p: p in PrimesUpTo(10^6) | Set(Intseq(p)) subset [0, 1, 2, 3, 4, 5, 6, 8]];
    
  • Mathematica
    Select[Prime[Range[120]], DigitCount[#, 10, 7] == 0 && DigitCount[#, 10, 9] == 0 &]
  • PARI
    primes_with(, 1, [0, 1, 2, 3, 4, 5, 6, 8]) \\ uses function in A385776
  • Python
    print(list(islice(primes_with("01234568"), 41))) # uses function/imports in A385776
    

A036962 Primes without {8, 9} as digits.

Original entry on oeis.org

2, 3, 5, 7, 11, 13, 17, 23, 31, 37, 41, 43, 47, 53, 61, 67, 71, 73, 101, 103, 107, 113, 127, 131, 137, 151, 157, 163, 167, 173, 211, 223, 227, 233, 241, 251, 257, 263, 271, 277, 307, 311, 313, 317, 331, 337, 347, 353, 367, 373, 401, 421, 431, 433, 443, 457, 461
Offset: 1

Views

Author

Patrick De Geest, Jan 04 1999

Keywords

Crossrefs

Subsequence of A038617.

Programs

  • Mathematica
    Select[FromDigits/@Tuples[Range[0,7],3],PrimeQ] (* Harvey P. Dale, Apr 13 2017 *)

A360147 Primes in base 10 that are also prime when read in a smaller base that is one plus the largest digit in the prime in base 10.

Original entry on oeis.org

2, 3, 5, 7, 11, 13, 23, 31, 37, 43, 61, 73, 101, 103, 107, 113, 131, 151, 223, 227, 233, 241, 251, 277, 307, 311, 331, 337, 373, 401, 461, 463, 467, 521, 547, 557, 577, 661, 673, 701, 827, 887, 1013, 1033, 1103, 1151, 1181, 1213, 1223, 1231, 1301, 1327, 1567
Offset: 1

Views

Author

Alfred Jacob Mohan, Jan 27 2023

Keywords

Crossrefs

Subsequence of A038617.

Programs

  • Maple
    q:= n-> isprime(n) and (l-> (d-> d<9 and isprime(add(l[i]*
       (d+1)^(i-1), i=1..nops(l))))(max(l)))(convert(n, base, 10)):
    select(q, [$1..2000])[];  # Alois P. Heinz, Jan 27 2023
  • Mathematica
    q[p_] := Module[{d = IntegerDigits[p], b}, b = Max[d] + 1; b <= 9 && PrimeQ[FromDigits[d, b]]]; Select[Prime[Range[250]], q] (* Amiram Eldar, Jan 27 2023 *)
  • PARI
    isok(p)=if(isprime(p), my(v=digits(p), b=vecmax(v)+1); b<10 && isprime(fromdigits(v,b)), 0) \\ Andrew Howroyd, Jan 27 2023
  • Python
    from sympy import isprime
    def ok(n):
        if not isprime(n): return False
        s = str(n)
        b = int(max(s)) + 1
        return b != 10 and isprime(int(s, b))
    print([k for k in range(1600) if ok(k)]) # Michael S. Branicky, Jan 27 2023
    

Extensions

More terms from Michael S. Branicky, Jan 27 2023

A386327 Primes without {0, 9} as digits.

Original entry on oeis.org

2, 3, 5, 7, 11, 13, 17, 23, 31, 37, 41, 43, 47, 53, 61, 67, 71, 73, 83, 113, 127, 131, 137, 151, 157, 163, 167, 173, 181, 211, 223, 227, 233, 241, 251, 257, 263, 271, 277, 281, 283, 311, 313, 317, 331, 337, 347, 353, 367, 373, 383, 421, 431, 433, 443, 457, 461
Offset: 1

Views

Author

Jason Bard, Jul 19 2025

Keywords

Crossrefs

Intersection of A038617 and A038618.

Programs

  • Magma
    [p: p in PrimesUpTo(10^6) | Set(Intseq(p)) subset [1, 2, 3, 4, 5, 6, 7, 8]];
    
  • Mathematica
    Select[Prime[Range[120]], DigitCount[#, 10, 0] == 0 && DigitCount[#, 10, 9] == 0 &]
  • PARI
    primes_with(, 1, [1, 2, 3, 4, 5, 6, 7, 8]) \\ uses function in A385776
  • Python
    print(list(islice(primes_with("12345678"), 41))) # uses function/imports in A385776
    

A386339 Primes without {2, 9} as digits.

Original entry on oeis.org

3, 5, 7, 11, 13, 17, 31, 37, 41, 43, 47, 53, 61, 67, 71, 73, 83, 101, 103, 107, 113, 131, 137, 151, 157, 163, 167, 173, 181, 307, 311, 313, 317, 331, 337, 347, 353, 367, 373, 383, 401, 431, 433, 443, 457, 461, 463, 467, 487, 503, 541, 547, 557, 563, 571, 577
Offset: 1

Views

Author

Jason Bard, Jul 19 2025

Keywords

Crossrefs

Intersection of A038604 and A038617.

Programs

  • Magma
    [p: p in PrimesUpTo(10^6) | Set(Intseq(p)) subset [0, 1, 3, 4, 5, 6, 7, 8]];
    
  • Mathematica
    Select[Prime[Range[120]], DigitCount[#, 10, 2] == 0 && DigitCount[#, 10, 9] == 0 &]
  • PARI
    primes_with(, 1, [0, 1, 3, 4, 5, 6, 7, 8]) \\ uses function in A385776
  • Python
    print(list(islice(primes_with("01345678"), 41))) # uses function/imports in A385776
    

A386344 Primes without {3, 9} as digits.

Original entry on oeis.org

2, 5, 7, 11, 17, 41, 47, 61, 67, 71, 101, 107, 127, 151, 157, 167, 181, 211, 227, 241, 251, 257, 271, 277, 281, 401, 421, 457, 461, 467, 487, 521, 541, 547, 557, 571, 577, 587, 601, 607, 617, 641, 647, 661, 677, 701, 727, 751, 757, 761, 787, 811, 821, 827, 857
Offset: 1

Views

Author

Jason Bard, Jul 20 2025

Keywords

Crossrefs

Intersection of A038611 and A038617.

Programs

  • Magma
    [p: p in PrimesUpTo(10^6) | Set(Intseq(p)) subset [0, 1, 2, 4, 5, 6, 7, 8]];
    
  • Mathematica
    Select[Prime[Range[120]], DigitCount[#, 10, 3] == 0 && DigitCount[#, 10, 9] == 0 &]
  • PARI
    primes_with(, 1, [0, 1, 2, 4, 5, 6, 7, 8]) \\ uses function in A385776
  • Python
    print(list(islice(primes_with("01245678"), 41))) # uses function/imports in A385776
    

A386349 Primes without {4, 9} as digits.

Original entry on oeis.org

2, 3, 5, 7, 11, 13, 17, 23, 31, 37, 53, 61, 67, 71, 73, 83, 101, 103, 107, 113, 127, 131, 137, 151, 157, 163, 167, 173, 181, 211, 223, 227, 233, 251, 257, 263, 271, 277, 281, 283, 307, 311, 313, 317, 331, 337, 353, 367, 373, 383, 503, 521, 523, 557, 563, 571
Offset: 1

Views

Author

Jason Bard, Jul 20 2025

Keywords

Crossrefs

Intersection of A038612 and A038617.

Programs

  • Magma
    [p: p in PrimesUpTo(10^6) | Set(Intseq(p)) subset [0, 1, 2, 3, 5, 6, 7, 8]];
    
  • Mathematica
    Select[Prime[Range[120]], DigitCount[#, 10, 4] == 0 && DigitCount[#, 10, 9] == 0 &]
  • PARI
    primes_with(, 1, [0, 1, 2, 3, 5, 6, 7, 8]) \\ uses function in A385776
  • Python
    print(list(islice(primes_with("01235678"), 41))) # uses function/imports in A385776
    

A386353 Primes without {5, 9} as digits.

Original entry on oeis.org

2, 3, 7, 11, 13, 17, 23, 31, 37, 41, 43, 47, 61, 67, 71, 73, 83, 101, 103, 107, 113, 127, 131, 137, 163, 167, 173, 181, 211, 223, 227, 233, 241, 263, 271, 277, 281, 283, 307, 311, 313, 317, 331, 337, 347, 367, 373, 383, 401, 421, 431, 433, 443, 461, 463, 467
Offset: 1

Views

Author

Jason Bard, Jul 20 2025

Keywords

Crossrefs

Intersection of A038613 and A038617.

Programs

  • Magma
    [p: p in PrimesUpTo(10^6) | Set(Intseq(p)) subset [0, 1, 2, 3, 4, 6, 7, 8]];
    
  • Mathematica
    Select[Prime[Range[120]], DigitCount[#, 10, 5] == 0 && DigitCount[#, 10, 9] == 0 &]
  • PARI
    primes_with(, 1, [0, 1, 2, 3, 4, 6, 7, 8]) \\ uses function in A385776
  • Python
    print(list(islice(primes_with("01234678"), 41))) # uses function/imports in A385776
    
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