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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A212525 Primes containing a digit 3.

Original entry on oeis.org

3, 13, 23, 31, 37, 43, 53, 73, 83, 103, 113, 131, 137, 139, 163, 173, 193, 223, 233, 239, 263, 283, 293, 307, 311, 313, 317, 331, 337, 347, 349, 353, 359, 367, 373, 379, 383, 389, 397, 431, 433, 439, 443, 463, 503, 523, 563, 593, 613, 631, 643, 653, 673, 683
Offset: 1

Views

Author

Jaroslav Krizek, Jun 12 2012

Keywords

Comments

Supersequence of A045709, A106103 and A106099. Subsequence of A011533 and A062667.

Crossrefs

Cf. A045709 (primes with first digit 3), A011533 (numbers containing a digit 3), A062667 (numbers n such that every divisor of n (except 1) contains the digit 3), A106099 (primes with maximal digit = 3), A106103 (primes with minimal digit = 3), A038611 (primes not containing digit 3).

Programs

  • Mathematica
    Select[Prime[Range[200]], MemberQ[IntegerDigits[#], 3] &] (* T. D. Noe, Jun 12 2012 *)

Formula

a(n) ~ n log n. - Charles R Greathouse IV, Nov 01 2022

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

A380906 Primes without {3, 5} as digits.

Original entry on oeis.org

2, 7, 11, 17, 19, 29, 41, 47, 61, 67, 71, 79, 89, 97, 101, 107, 109, 127, 149, 167, 179, 181, 191, 197, 199, 211, 227, 229, 241, 269, 271, 277, 281, 401, 409, 419, 421, 449, 461, 467, 479, 487, 491, 499, 601, 607, 617, 619, 641, 647, 661, 677, 691, 701, 709, 719, 727, 761, 769, 787, 797
Offset: 1

Views

Author

Vincenzo Librandi, Feb 09 2025

Keywords

Crossrefs

Intersection of A038611 and A038613.

Programs

  • Magma
    [p: p in PrimesUpTo(700) | not 3 in Intseq(p) and not 5 in Intseq(p) ];
    
  • Mathematica
    Select[Prime[Range[120]],DigitCount[#,10,3]==0&&DigitCount[#,10,5]==0&]
  • PARI
    isok(p) = if (isprime(p), my(d=digits(p)); (#select(x->(x==3), d)==0) && (#select(x->(x==5), d)==0)); \\ Michel Marcus, Feb 10 2025
    
  • Python
    from itertools import count, islice
    from sympy import isprime
    def A380906_gen(): # generator of terms
        return filter(isprime,(int(oct(n)[2:].translate({51:52,52:54,53:55,54:56,55:57})) for n in count(1)))
    A380906_list = list(islice(A380906_gen(),20)) # Chai Wah Wu, Feb 12 2025

A224320 Primes without "3" as a digit that remain prime when any single digit is replaced with "3".

Original entry on oeis.org

2, 5, 7, 11, 17, 41, 47, 71, 107, 167, 179, 197, 449, 859, 1019, 1061, 1499, 2089, 16901, 47717, 56269, 86269, 11917049
Offset: 1

Views

Author

Arkadiusz Wesolowski, Apr 03 2013

Keywords

Comments

No more terms < 10^13.

Crossrefs

Cf. A224319, A224321-A224322. Subsequence of A038611.

Programs

  • Mathematica
    lst = {}; n = 3; 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, 86269}]; lst
    p3Q[n_]:=Module[{idn=IntegerDigits[n]},FreeQ[idn,3] && AllTrue[ FromDigits/@ Table[ReplacePart[idn,i->3],{i,IntegerLength[n]}],PrimeQ]]; Select[Prime[Range[10^6]],p3Q] (* The program uses the function AllTrue from Mathematica version 10 *) (* Harvey P. Dale, Aug 20 2014 *)

A386321 Primes without {0, 3} as digits.

Original entry on oeis.org

2, 5, 7, 11, 17, 19, 29, 41, 47, 59, 61, 67, 71, 79, 89, 97, 127, 149, 151, 157, 167, 179, 181, 191, 197, 199, 211, 227, 229, 241, 251, 257, 269, 271, 277, 281, 419, 421, 449, 457, 461, 467, 479, 487, 491, 499, 521, 541, 547, 557, 569, 571, 577, 587, 599, 617
Offset: 1

Views

Author

Jason Bard, Jul 19 2025

Keywords

Crossrefs

Intersection of A038611 and A038618.

Programs

  • Magma
    [p: p in PrimesUpTo(10^6) | Set(Intseq(p)) subset [1, 2, 4, 5, 6, 7, 8, 9]];
    
  • Mathematica
    Select[Prime[Range[120]], DigitCount[#, 10, 0] == 0 && DigitCount[#, 10, 3] == 0 &]
  • PARI
    primes_with(, 1, [1, 2, 4, 5, 6, 7, 8, 9]) \\ uses function in A385776
  • Python
    print(list(islice(primes_with("12456789"), 41))) # uses function/imports in A385776
    

A386329 Primes without {1, 3} as digits.

Original entry on oeis.org

2, 5, 7, 29, 47, 59, 67, 79, 89, 97, 227, 229, 257, 269, 277, 409, 449, 457, 467, 479, 487, 499, 509, 547, 557, 569, 577, 587, 599, 607, 647, 659, 677, 709, 727, 757, 769, 787, 797, 809, 827, 829, 857, 859, 877, 887, 907, 929, 947, 967, 977, 997, 2027, 2029, 2069
Offset: 1

Views

Author

Jason Bard, Jul 19 2025

Keywords

Crossrefs

Intersection of A038603 and A038611.

Programs

  • Magma
    [p: p in PrimesUpTo(10^6) | Set(Intseq(p)) subset [0, 2, 4, 5, 6, 7, 8, 9]];
    
  • Mathematica
    Select[Prime[Range[120]], DigitCount[#, 10, 1] == 0 && DigitCount[#, 10, 3] == 0 &]
  • PARI
    primes_with(, 1, [0, 2, 4, 5, 6, 7, 8, 9]) \\ uses function in A385776
  • Python
    print(list(islice(primes_with("02456789"), 41))) # uses function/imports in A385776
    

A386335 Primes without {2, 3} as digits.

Original entry on oeis.org

5, 7, 11, 17, 19, 41, 47, 59, 61, 67, 71, 79, 89, 97, 101, 107, 109, 149, 151, 157, 167, 179, 181, 191, 197, 199, 401, 409, 419, 449, 457, 461, 467, 479, 487, 491, 499, 509, 541, 547, 557, 569, 571, 577, 587, 599, 601, 607, 617, 619, 641, 647, 659, 661, 677, 691
Offset: 1

Views

Author

Jason Bard, Jul 19 2025

Keywords

Crossrefs

Intersection of A038604 and A038611.

Programs

  • Magma
    [p: p in PrimesUpTo(10^6) | Set(Intseq(p)) subset [0, 1, 4, 5, 6, 7, 8, 9]];
    
  • Mathematica
    Select[Prime[Range[120]], DigitCount[#, 10, 2] == 0 && DigitCount[#, 10, 3] == 0 &]
  • PARI
    primes_with(, 1, [0, 1, 4, 5, 6, 7, 8, 9]) \\ uses function in A385776
  • Python
    print(list(islice(primes_with("01456789"), 41))) # uses function/imports in A385776
    

A386340 Primes without {3, 4} as digits.

Original entry on oeis.org

2, 5, 7, 11, 17, 19, 29, 59, 61, 67, 71, 79, 89, 97, 101, 107, 109, 127, 151, 157, 167, 179, 181, 191, 197, 199, 211, 227, 229, 251, 257, 269, 271, 277, 281, 509, 521, 557, 569, 571, 577, 587, 599, 601, 607, 617, 619, 659, 661, 677, 691, 701, 709, 719, 727, 751
Offset: 1

Views

Author

Jason Bard, Jul 19 2025

Keywords

Crossrefs

Intersection of A038611 and A038612.

Programs

  • Magma
    [p: p in PrimesUpTo(10^6) | Set(Intseq(p)) subset [0, 1, 2, 5, 6, 7, 8, 9]];
    
  • Maple
    f:= n-> (l-> add([$0..2, $5..9][l[j]+1]*10^(j-1), j=1..nops(l)))(convert(n, base, 8)):
    select(isprime, [seq(f(i), i=0..600)])[];  # Alois P. Heinz, Jul 19 2025
  • Mathematica
    Select[Prime[Range[120]], DigitCount[#, 10, 3] == 0 && DigitCount[#, 10, 4] == 0 &]
  • PARI
    primes_with(, 1, [0, 1, 2, 5, 6, 7, 8, 9]) \\ uses function in A385776
  • Python
    print(list(islice(primes_with("01256789"), 41))) # uses function/imports in A385776
    

A386341 Primes without {3, 6} as digits.

Original entry on oeis.org

2, 5, 7, 11, 17, 19, 29, 41, 47, 59, 71, 79, 89, 97, 101, 107, 109, 127, 149, 151, 157, 179, 181, 191, 197, 199, 211, 227, 229, 241, 251, 257, 271, 277, 281, 401, 409, 419, 421, 449, 457, 479, 487, 491, 499, 509, 521, 541, 547, 557, 571, 577, 587, 599, 701, 709
Offset: 1

Views

Author

Jason Bard, Jul 20 2025

Keywords

Crossrefs

Intersection of A038611 and A038614.

Programs

  • Magma
    [p: p in PrimesUpTo(10^6) | Set(Intseq(p)) subset [0, 1, 2, 4, 5, 7, 8, 9]];
    
  • Mathematica
    Select[Prime[Range[120]], DigitCount[#, 10, 3] == 0 && DigitCount[#, 10, 6] == 0 &]
  • PARI
    primes_with(, 1, [0, 1, 2, 4, 5, 7, 8, 9]) \\ uses function in A385776
  • Python
    print(list(islice(primes_with("01245789"), 41))) # uses function/imports in A385776
    

A386342 Primes without {3, 7} as digits.

Original entry on oeis.org

2, 5, 11, 19, 29, 41, 59, 61, 89, 101, 109, 149, 151, 181, 191, 199, 211, 229, 241, 251, 269, 281, 401, 409, 419, 421, 449, 461, 491, 499, 509, 521, 541, 569, 599, 601, 619, 641, 659, 661, 691, 809, 811, 821, 829, 859, 881, 911, 919, 929, 941, 991, 1009, 1019
Offset: 1

Views

Author

Jason Bard, Jul 20 2025

Keywords

Crossrefs

Intersection of A038611 and A038615.

Programs

  • Magma
    [p: p in PrimesUpTo(10^6) | Set(Intseq(p)) subset [0, 1, 2, 4, 5, 6, 8, 9]];
    
  • Mathematica
    Select[Prime[Range[120]], DigitCount[#, 10, 3] == 0 && DigitCount[#, 10, 7] == 0 &]
  • PARI
    primes_with(, 1, [0, 1, 2, 4, 5, 6, 8, 9]) \\ uses function in A385776
  • Python
    print(list(islice(primes_with("01245689"), 41))) # uses function/imports in A385776
    
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