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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A168046 Characteristic function of zerofree numbers in decimal representation.

Original entry on oeis.org

0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0
Offset: 0

Views

Author

Reinhard Zumkeller, Dec 01 2009

Keywords

Comments

a(A052382(n)) = 1; a(A011540(n)) = 0;
a(n) = A000007(A055641(n));
not the same as A168184: a(n)=A168184(n) for n<=100.
a(A007602(n)) = a(A038186(n)) = 1. - Reinhard Zumkeller, Apr 07 2011

Crossrefs

Programs

  • Haskell
    a168046 = fromEnum . ch0 where
       ch0 x = x > 0 && (x < 10 || d > 0 && ch0 x') where (x', d) = divMod x 10
    -- Reinhard Zumkeller, May 10 2015, Apr 07 2011
  • Mathematica
    Map[Boole[FreeQ[IntegerDigits[#], 0]] &, Range[0, 100]] (* Paolo Xausa, May 06 2024 *)

Formula

a(n) = A057427(A010879(n)) * (if n<10 then 1 else a(A059995(n))).
From Hieronymus Fischer, Jan 23 2013: (Start)
a(n) = A057427(A007954(n)) = sign(dp_10(n)).
where dp_10(n) digital product of n in base 10.
a(n) = 1 - A217096(n).
a(n) = 1 - sign(A055641(n)).
g(x) = x(1-x^9)/((1-x)(1-x^10))(1 + sum_{j>=1} (x^((10^j-10)/9) - x^10^j)/(1-x^10^(j+1)))).
g(x) = 1/(1-x) - g_A217096(x), where g_A217096(x) is the g.f. of A217096.
(End)

A195908 Powers of 7 which have no zero in their decimal expansion.

Original entry on oeis.org

1, 7, 49, 343, 117649, 823543, 282475249, 1977326743, 11398895185373143, 378818692265664781682717625943
Offset: 1

Views

Author

M. F. Hasler, Sep 25 2011

Keywords

Comments

Probably finite. Is 378818692265664781682717625943 the largest term?
No further terms up to 7^50,000, a number with 42,255 digits. - Harvey P. Dale, Jul 14 2022

Crossrefs

Programs

  • Magma
    [7^n: n in [0..3*10^4] | not 0 in Intseq(7^n)]; // Bruno Berselli, Sep 26 2011
  • Mathematica
    Select[7^Range[0,50],DigitCount[#,10,0]==0&] (* Harvey P. Dale, Jul 14 2022 *)
  • PARI
    for( n=1,9999, is_A052382(7^n) && print1(7^n,","))
    

Formula

a(n) = 7^A030703(n).
A000420 intersect A052382.

Extensions

Keyword:fini removed by Jianing Song, Jan 28 2023 as finiteness is only conjectured.

A195946 Powers of 11 which have no zero in their decimal expansion.

Original entry on oeis.org

1, 11, 121, 1331, 14641, 1771561, 19487171, 214358881, 2357947691, 3138428376721, 34522712143931, 379749833583241, 4177248169415651, 45949729863572161, 5559917313492231481, 4978518112499354698647829163838661251242411
Offset: 1

Views

Author

M. F. Hasler, Sep 25 2011

Keywords

Comments

Probably finite. Is 4978518112499354698647829163838661251242411 the largest term?

Crossrefs

For the zeroless numbers (powers x^n), see A195942, A195943, A238938, A238939, A238940, A195948, A238936, A195908, A195945.
For the corresponding exponents, see A007377, A008839, A030700, A030701, A030702, A030703, A030704, A030705, A030706, A195944.

Programs

  • Magma
    [11^n: n in [0..3*10^4] | not 0 in Intseq(11^n)]; // Bruno Berselli, Sep 26 2011
  • Mathematica
    Select[11^Range[0,50],DigitCount[#,10,0]==0&] (* Harvey P. Dale, Jan 27 2014 *)
  • PARI
    for( n=0,9999, is_A052382(11^n) && print1(11^n,","))
    

Formula

a(n) = 11^A030706(n).
A195946 = A001020 intersect A052382.

Extensions

Keyword:fini removed by Jianing Song, Jan 28 2023 as finiteness is only conjectured.

A052041 Squares lacking the digit zero in their decimal expansion.

Original entry on oeis.org

1, 4, 9, 16, 25, 36, 49, 64, 81, 121, 144, 169, 196, 225, 256, 289, 324, 361, 441, 484, 529, 576, 625, 676, 729, 784, 841, 961, 1156, 1225, 1296, 1369, 1444, 1521, 1681, 1764, 1849, 1936, 2116, 2916, 3136, 3249, 3364, 3481, 3721, 3844, 3969, 4225, 4356
Offset: 1

Views

Author

Patrick De Geest, Dec 15 1999

Keywords

Comments

This sequence is infinite: see A075415 or A102807 for a constructive proof.
Intersection of A052382 and A000290; A168046(a(n))*A010052(a(n))=1. - Reinhard Zumkeller, Dec 01 2009

Crossrefs

Programs

  • Mathematica
    Select[Range[66]^2, FreeQ[IntegerDigits[#],0]==True &] (* Jayanta Basu, May 25 2013 *)

Formula

a(n) = A052040(n)^2. - R. J. Mathar, Jul 23 2025

A195945 Powers of 13 which have no zero in their decimal expansion.

Original entry on oeis.org

1, 13, 169, 2197, 28561, 371293, 62748517, 137858491849, 3937376385699289
Offset: 1

Views

Author

M. F. Hasler, Sep 25 2011

Keywords

Comments

Probably finite. Is 3937376385699289 the largest term?
No further terms up to 13^25000. - Harvey P. Dale, Oct 01 2011
No further terms up to 13^45000. - Vincenzo Librandi, Jul 31 2013
No further terms up to 13^(10^9). - Daniel Starodubtsev, Mar 22 2020

Crossrefs

For other zeroless powers x^n, see A238938 (x=2), A238939, A238940, A195948, A238936, A195908, A195946 (x=11), A195945, A195942, A195943, A103662.
For the corresponding exponents, see A007377, A008839, A030700, A030701, A008839, A030702, A030703, A030704, A030705, A030706, A195944 and also A020665.
For other related sequences, see A052382, A027870, A102483, A103663.

Programs

  • Magma
    [13^n: n in [0..2*10^4] | not 0 in Intseq(13^n)]; // Bruno Berselli, Sep 26 2011
  • Mathematica
    Select[13^Range[0,250],DigitCount[#,10,0]==0&] (* Harvey P. Dale, Oct 01 2011 *)
  • PARI
    for(n=0,9999, is_A052382(13^n) && print1(13^n,","))
    

Formula

Equals A001022 intersect A052382 (as a set).
Equals A001022 o A195944 (as a function).

A195944 Numbers k such that 13^k has no zero in its decimal expansion.

Original entry on oeis.org

0, 1, 2, 3, 4, 5, 7, 10, 14
Offset: 1

Views

Author

M. F. Hasler, Sep 25 2011

Keywords

Comments

Probably finite. Is 14 the largest term?

Crossrefs

Programs

  • Magma
    [n: n in [0..1000] | not 0 in Intseq(13^n) ]; // Vincenzo Librandi, May 06 2015
  • Mathematica
    Select[Range[0,20],DigitCount[13^#,10,0]==0&] (* Harvey P. Dale, May 24 2023 *)
  • PARI
    for( n=0,9999, is_A052382(13^n) && print1(n","))
    

Formula

Equals { n | A001022(n) is in A052382 }.

Extensions

Keyword:fini removed by Jianing Song, Jan 28 2023 as finiteness is only conjectured.

A052040 Numbers whose square is zeroless.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 24, 25, 26, 27, 28, 29, 31, 34, 35, 36, 37, 38, 39, 41, 42, 43, 44, 46, 54, 56, 57, 58, 59, 61, 62, 63, 65, 66, 67, 68, 69, 72, 73, 74, 75, 76, 77, 79, 81, 82, 83, 85, 86, 87, 88, 89, 91, 92, 93, 94, 96
Offset: 1

Views

Author

Patrick De Geest, Dec 15 1999

Keywords

Comments

This sequence is infinite, since 33...334^2 = 11...11155...556, for example. This answers an open problem stated in HAKMEM. - Karl W. Heuer, Aug 19 2015

Examples

			From _Jon E. Schoenfield_, Aug 16 2021: (Start)
31 is a term: 31^2 = 961 has no 0's among its digits.
32 is not a term, because 32^2 = 1024. (End)
		

Crossrefs

Programs

A195948 Powers of 5 which have no zero in their decimal expansion.

Original entry on oeis.org

1, 5, 25, 125, 625, 3125, 15625, 78125, 1953125, 9765625, 48828125, 762939453125, 3814697265625, 931322574615478515625, 116415321826934814453125, 34694469519536141888238489627838134765625
Offset: 1

Views

Author

M. F. Hasler, Sep 25 2011

Keywords

Comments

Probably finite. Is 34694469519536141888238489627838134765625 the largest term?

Crossrefs

Programs

  • Mathematica
    Select[5^Range[0,60],DigitCount[#,10,0]==0&] (* Harvey P. Dale, Aug 30 2016 *)
  • PARI
    for( n=0,9999, is_A052382(5^n) && print1(5^n,","))

Formula

a(n) = 5^A008839(n).
A000351 intersect A052382.

Extensions

Keyword:fini removed by Jianing Song, Jan 28 2023 as finiteness is only conjectured.

A052405 Numbers without 3 as a digit.

Original entry on oeis.org

0, 1, 2, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 15, 16, 17, 18, 19, 20, 21, 22, 24, 25, 26, 27, 28, 29, 40, 41, 42, 44, 45, 46, 47, 48, 49, 50, 51, 52, 54, 55, 56, 57, 58, 59, 60, 61, 62, 64, 65, 66, 67, 68, 69, 70, 71, 72, 74, 75, 76, 77, 78, 79, 80, 81, 82, 84, 85, 86, 87, 88, 89
Offset: 1

Views

Author

Henry Bottomley, Mar 13 2000

Keywords

Comments

This sequence also represents the minimal number of straight lines of a covering tree to cover n X n points arranged in a symmetrical grid. - Marco RipĂ , Sep 20 2018

Examples

			22 has no 3s among its digits, hence it is in the sequence.
23 has one 3 among its digits, hence it is not in the sequence.
		

Crossrefs

Cf. A004178, A004722, A038611 (subset of primes), A082832 (Kempner series).
Cf. A052382 (without 0), A052383 (without 1), A052404 (without 2), A052406 (without 4), A052413 (without 5), A052414 (without 6), A052419 (without 7), A052421 (without 8), A007095 (without 9).
Cf. A011533 (complement).

Programs

  • Haskell
    a052405 = f . subtract 1 where
       f 0 = 0
       f v = 10 * f w + if r > 2 then r + 1 else r  where (w, r) = divMod v 9
    -- Reinhard Zumkeller, Oct 07 2014
    
  • Magma
    [ n: n in [0..89] | not 3 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<3, 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
    Select[Range[0, 89], DigitCount[#, 10, 3] == 0 &] (* Alonso del Arte, Oct 16 2012 *)
  • PARI
    is(n)=n=digits(n);for(i=1,#n,if(n[i]==3,return(0)));1 \\ Charles R Greathouse IV, Oct 16 2012
    apply( {A052405(n)=fromdigits(apply(d->d+(d>2),digits(n-1,9)))}, [1..99]) \\ a(n)
    next_A052405(n, d=digits(n+=1))={for(i=1, #d, d[i]==3&& return((1+n\d=10^(#d-i))*d)); n} \\ least a(k) > n. Used in A038611. \\ M. F. Hasler, Jan 11 2020
    
  • Python
    from gmpy2 import digits
    def A052405(n): return int(digits(n-1,9).translate(str.maketrans('345678','456789'))) # Chai Wah Wu, Jun 28 2025
  • sh
    seq 0 1000 | grep -v 3; # Joerg Arndt, May 29 2011
    

Formula

a(n) >> n^k with k = log(10)/log(9) = 1.0479.... - Charles R Greathouse IV, Oct 16 2012
a(n) = replace digits d > 2 by d + 1 in base-9 representation of n - 1. - Reinhard Zumkeller, Oct 07 2014
Sum_{n>1} 1/a(n) = A082832 = 20.569877... (Kempner series). - Bernard Schott, Jan 12 2020, edited by M. F. Hasler, Jan 14 2020

Extensions

Offset changed by Reinhard Zumkeller, Oct 07 2014

A052413 Numbers without 5 as a digit.

Original entry on oeis.org

0, 1, 2, 3, 4, 6, 7, 8, 9, 10, 11, 12, 13, 14, 16, 17, 18, 19, 20, 21, 22, 23, 24, 26, 27, 28, 29, 30, 31, 32, 33, 34, 36, 37, 38, 39, 40, 41, 42, 43, 44, 46, 47, 48, 49, 60, 61, 62, 63, 64, 66, 67, 68, 69, 70, 71, 72, 73, 74, 76, 77, 78, 79, 80, 81, 82, 83, 84, 86, 87, 88, 89
Offset: 1

Views

Author

Henry Bottomley, Mar 13 2000

Keywords

Crossrefs

Cf. A004180, A004724, A038613 (subset of primes), A082834 (Kempner series).
Cf. A052382 (without 0), A052383 (without 1), A052404 (without 2), A052405 (without 3), A052406 (without 4), A052414 (without 6), A052419 (without 7), A052421 (without 8), A007095 (without 9).

Programs

  • Haskell
    a052413 = f . subtract 1 where
    f 0 = 0
    f v = 10 * f w + if r > 4 then r + 1 else r where (w, r) = divMod v 9
    -- Reinhard Zumkeller, Oct 07 2014
    
  • Magma
    [ n: n in [0..89] | not 5 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<5, 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
    Select[Range[100],!MemberQ[IntegerDigits[#],5]&] (* Harvey P. Dale, Feb 20 2013 *)
  • PARI
    apply( {A052413(n)=fromdigits(apply(d->d+(d>4),digits(n-1,9)))}, [1..99]) \\ a(n)
    select( {is_A052413(n)=!setsearch(Set(digits(n)),5)}, [0..99]) \\ used in A038613
    next_A052413(n, d=digits(n+=1))={for(i=1,#d, d[i]==5&&return((1+n\d=10^(#d-i))*d)); n} \\ least a(k) > n; used in A038613. - M. F. Hasler, Jan 11 2020
    
  • Python
    # see the OEIS wiki page (cf. LINKS) for more programs
    def A052413(n): n-=1; return sum(n//9**e%9*6//5*10**e for e in range(math.ceil(math.log(n+1,9)))) # M. F. Hasler, Jan 13 2020
    
  • Python
    from gmpy2 import digits
    def A052413(n): return int(digits(n-1,9).translate(str.maketrans('5678','6789'))) # Chai Wah Wu, Jun 28 2025
  • sh
    seq 0 1000 | grep -v 5; # Joerg Arndt, May 29 2011
    

Formula

a(n) = replace digits d > 4 by d + 1 in base-9 representation of n - 1. - Reinhard Zumkeller, Oct 07 2014
Sum_{k>1} 1/a(n) = A082834 = 21.8346008... (Kempner series). - Bernard Schott, Jan 12 2020, edited by M. F. Hasler, Jan 13 2020

Extensions

Offset changed by Reinhard Zumkeller, Oct 07 2014
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