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.

Previous Showing 11-20 of 20 results.

A052404 Numbers without 2 as a digit.

Original entry on oeis.org

0, 1, 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 14, 15, 16, 17, 18, 19, 30, 31, 33, 34, 35, 36, 37, 38, 39, 40, 41, 43, 44, 45, 46, 47, 48, 49, 50, 51, 53, 54, 55, 56, 57, 58, 59, 60, 61, 63, 64, 65, 66, 67, 68, 69, 70, 71, 73, 74, 75, 76, 77, 78, 79, 80, 81, 83, 84, 85, 86, 87, 88, 89
Offset: 1

Views

Author

Henry Bottomley, Mar 13 2000

Keywords

References

  • M. J. Halm, Word Weirdness, Mpossibilities 66 (Feb. 1998), p. 5.

Crossrefs

Cf. A004177, A004721, A072809, A082831 (Kempner series).
Cf. A052382 (without 0), A052383 (without 1), A052405 (without 3), A052406 (without 4), A052413 (without 5), A052414 (without 6), A052419 (without 7), A052421 (without 8), A007095 (without 9).
See A038604 for the subset of primes. - M. F. Hasler, Jan 11 2020

Programs

  • Haskell
    a052404 = f . subtract 1 where
       f 0 = 0
       f v = 10 * f w + if r > 1 then r + 1 else r  where (w, r) = divMod v 9
    -- Reinhard Zumkeller, Oct 07 2014
    
  • Magma
    [ n: n in [0..89] | not 2 in Intseq(n) ];  // Bruno Berselli, May 28 2011
    
  • Maple
    a:= proc(n) local l, m; l, m:= 0, n-1;
          while m>0 do l:= (d->
            `if`(d<2, d, d+1))(irem(m, 9, 'm')), l
          od; parse(cat(l))/10
        end:
    seq(a(n), n=1..100);  # Alois P. Heinz, Aug 01 2016
  • Mathematica
    ban2Q[n_]:=FreeQ[IntegerDigits[n],2]==True; Select[Range[0,89],ban2Q[#] &] (* Jayanta Basu, May 17 2013 *)
    Select[Range[0,100],DigitCount[#,10,2]==0&] (* Harvey P. Dale, Apr 13 2015 *)
  • PARI
    lista(nn, d=2) = {for (n=0, nn, if (!vecsearch(vecsort(digits(n),,8),d), print1(n, ", ")););} \\ Michel Marcus, Feb 21 2015
    
  • PARI
    apply( {A052404(n)=fromdigits(apply(d->d+(d>1),digits(n-1,9)))}, [1..99])
    next_A052404(n, d=digits(n+=1))={for(i=1, #d, d[i]==2&&return((1+n\d=10^(#d-i))*d)); n} \\ least a(k) > n: if there's a digit 2 in n+1, replace the first occurrence by 3 and all following digits by 0.
    (A052404_vec(N)=vector(N, i, N=if(i>1, next_A052404(N))))(99) \\ first N terms
    select( {is_A052404(n)=!setsearch(Set(digits(n)),2)}, [0..99])
    (A052404_upto(N)=select( is_A052404, [0..N]))(99) \\ M. F. Hasler, Jan 11 2020
    
  • Python
    from gmpy2 import digits
    def A052404(n): return int(''.join(str(int(d)+1) if d>'1' else d for d in digits(n-1,9))) # Chai Wah Wu, Aug 30 2024
  • sh
    seq 0 1000 | grep -v 2; # Joerg Arndt, May 29 2011
    

Formula

If the offset were changed to 0: a(0) = 0, a(n+1) = f(a(n)+1,a(n)+1) where f(x,y) = if x<10 and x<>2 then y else if x mod 10 = 2 then f(y+1,y+1) else f(floor(x/10),y). - Reinhard Zumkeller, Mar 02 2008
a(n) = replace digits d > 1 by d + 1 in base-9 representation of n - 1. - Reinhard Zumkeller, Oct 07 2014
Sum_{k>1} 1/a(k) = A082831 = 19.257356... (Kempner series). - Bernard Schott, Jan 12 2020, edited by M. F. Hasler, Jan 14 2020

Extensions

Offset changed by Reinhard Zumkeller, Oct 07 2014

A329760 Primes without {2, 7} as digits.

Original entry on oeis.org

3, 5, 11, 13, 19, 31, 41, 43, 53, 59, 61, 83, 89, 101, 103, 109, 113, 131, 139, 149, 151, 163, 181, 191, 193, 199, 311, 313, 331, 349, 353, 359, 383, 389, 401, 409, 419, 431, 433, 439, 443, 449, 461, 463, 491, 499, 503, 509, 541, 563, 569, 593, 599, 601, 613
Offset: 1

Views

Author

Alois P. Heinz, Nov 20 2019

Keywords

Crossrefs

Programs

  • Magma
    [p: p in PrimesUpTo(700) | not 2 in Intseq(p) and not 7 in Intseq(p) ]; // Vincenzo Librandi, Jan 02 2020
  • Mathematica
    Select[Prime[Range[120]], DigitCount[#, 10, 2]==0 && DigitCount[#, 10, 7]==0 &] (* Vincenzo Librandi, Jan 02 2020 *)

Formula

{ A038604 } intersect { A038615 }.

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

A386320 Primes without {0, 2} as digits.

Original entry on oeis.org

3, 5, 7, 11, 13, 17, 19, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 113, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 311, 313, 317, 331, 337, 347, 349, 353, 359, 367, 373, 379, 383, 389, 397, 419, 431, 433, 439
Offset: 1

Views

Author

Jason Bard, Jul 18 2025

Keywords

Crossrefs

Intersection of A038604 and A038618.

Programs

  • Magma
    [p: p in PrimesUpTo(10^6) | Set(Intseq(p)) subset [1, 3, 4, 5, 6, 7, 8, 9]];
    
  • Mathematica
    Select[Prime[Range[120]], DigitCount[#, 10, 0] == 0 && DigitCount[#, 10, 2] == 0 &]
  • PARI
    primes_with(, 1, [1, 3, 4, 5, 6, 7, 8, 9]) \\ uses function in A385776
  • Python
    print(list(islice(primes_with("13456789"), 41))) # uses function/imports in A385776
    

A386328 Primes without {1, 2} as digits.

Original entry on oeis.org

3, 5, 7, 37, 43, 47, 53, 59, 67, 73, 79, 83, 89, 97, 307, 337, 347, 349, 353, 359, 367, 373, 379, 383, 389, 397, 409, 433, 439, 443, 449, 457, 463, 467, 479, 487, 499, 503, 509, 547, 557, 563, 569, 577, 587, 593, 599, 607, 643, 647, 653, 659, 673, 677, 683, 709
Offset: 1

Views

Author

Jason Bard, Jul 19 2025

Keywords

Crossrefs

Intersection of A038603 and A038604.

Programs

  • Magma
    [p: p in PrimesUpTo(10^6) | Set(Intseq(p)) subset [0, 3, 4, 5, 6, 7, 8, 9]];
    
  • Mathematica
    Select[Prime[Range[120]], DigitCount[#, 10, 1] == 0 && DigitCount[#, 10, 2] == 0 &]
  • PARI
    primes_with(, 1, [0, 3, 4, 5, 6, 7, 8, 9]) \\ uses function in A385776
  • Python
    print(list(islice(primes_with("03456789"), 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
    

A386336 Primes without {2, 4} as digits.

Original entry on oeis.org

3, 5, 7, 11, 13, 17, 19, 31, 37, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 131, 137, 139, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 307, 311, 313, 317, 331, 337, 353, 359, 367, 373, 379, 383, 389, 397, 503, 509, 557, 563, 569
Offset: 1

Views

Author

Jason Bard, Jul 19 2025

Keywords

Crossrefs

Intersection of A038604 and A038612.

Programs

  • Magma
    [p: p in PrimesUpTo(10^6) | Set(Intseq(p)) subset [0, 1, 3, 5, 6, 7, 8, 9]];
    
  • Maple
    f:= n-> (l-> add([0, 1, 3, $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, 2] == 0 && DigitCount[#, 10, 4] == 0 &]
  • PARI
    primes_with(, 1, [0, 1, 3, 5, 6, 7, 8, 9]) \\ uses function in A385776
  • Python
    print(list(islice(primes_with("01356789"), 41))) # uses function/imports in A385776
    

A386337 Primes without {2, 6} as digits.

Original entry on oeis.org

3, 5, 7, 11, 13, 17, 19, 31, 37, 41, 43, 47, 53, 59, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 131, 137, 139, 149, 151, 157, 173, 179, 181, 191, 193, 197, 199, 307, 311, 313, 317, 331, 337, 347, 349, 353, 359, 373, 379, 383, 389, 397, 401, 409, 419, 431
Offset: 1

Views

Author

Jason Bard, Jul 19 2025

Keywords

Crossrefs

Intersection of A038604 and A038614.

Programs

  • Magma
    [p: p in PrimesUpTo(10^6) | Set(Intseq(p)) subset [0, 1, 3, 4, 5, 7, 8, 9]];
    
  • Maple
    f:= n-> (l-> add([0, 1, $3..5, $7..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, 2] == 0 && DigitCount[#, 10, 6] == 0 &]
  • PARI
    primes_with(, 1, [0, 1, 3, 4, 5, 7, 8, 9]) \\ uses function in A385776
  • Python
    print(list(islice(primes_with("01345789"), 41))) # uses function/imports in A385776
    

A386338 Primes without {2, 8} as digits.

Original entry on oeis.org

3, 5, 7, 11, 13, 17, 19, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 97, 101, 103, 107, 109, 113, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 191, 193, 197, 199, 307, 311, 313, 317, 331, 337, 347, 349, 353, 359, 367, 373, 379, 397, 401, 409, 419, 431
Offset: 1

Views

Author

Jason Bard, Jul 19 2025

Keywords

Crossrefs

Intersection of A038604 and A038616.

Programs

  • Magma
    [p: p in PrimesUpTo(10^6) | Set(Intseq(p)) subset [0, 1, 3, 4, 5, 6, 7, 9]];
    
  • Maple
    f:= n-> (l-> add([0, 1, $3..7, 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, 2] == 0 && DigitCount[#, 10, 8] == 0 &]
  • PARI
    primes_with(, 1, [0, 1, 3, 4, 5, 6, 7, 9]) \\ uses function in A385776
  • Python
    print(list(islice(primes_with("01345679"), 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
    
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