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 11-18 of 18 results.

A033047 Sums of distinct powers of 11.

Original entry on oeis.org

0, 1, 11, 12, 121, 122, 132, 133, 1331, 1332, 1342, 1343, 1452, 1453, 1463, 1464, 14641, 14642, 14652, 14653, 14762, 14763, 14773, 14774, 15972, 15973, 15983, 15984, 16093, 16094, 16104, 16105, 161051, 161052, 161062, 161063, 161172
Offset: 0

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Author

Keywords

Comments

Numbers without any base-11 digits greater than 1.
a(n) modulo 2 is the Prouhet-Thue-Morse sequence A010060. - Philippe Deléham, Oct 17 2011

Crossrefs

Row 10 of array A104257.

Programs

  • Mathematica
    With[{k = 11}, Map[FromDigits[#, k] &, Tuples[{0, 1}, 6]]] (* Michael De Vlieger, Oct 28 2022 *)
  • PARI
    {for(vv=0,35,
    bvv=binary(vv);
    texp=0;btb=0;
    forstep(i=length(bvv),1,-1,btb=btb+bvv[i]*11^texp;texp++);
    print1(btb,", "))} \\ Douglas Latimer, May 12 2012
    
  • PARI
    a(n)=fromdigits(binary(n),11) \\ Charles R Greathouse IV, Jan 11 2017

Formula

a(n) = Sum_{i=0..m} d(i)*11^i, where Sum_{i=0..m} d(i)*2^i is the base-2 representation of n.
a(n) = A097257(n)/10.
a(2n) = 11*a(n), a(2n+1) = a(2n)+1.
a(n) = Sum_{k>=0} A030308(n,k)*11^k. - Philippe Deléham, Oct 17 2011
G.f.: (1/(1 - x))*Sum_{k>=0} 11^k*x^(2^k)/(1 + x^(2^k)). - Ilya Gutkovskiy, Jun 04 2017

Extensions

Extended by Ray Chandler, Aug 03 2004

A033049 Sums of distinct powers of 13.

Original entry on oeis.org

0, 1, 13, 14, 169, 170, 182, 183, 2197, 2198, 2210, 2211, 2366, 2367, 2379, 2380, 28561, 28562, 28574, 28575, 28730, 28731, 28743, 28744, 30758, 30759, 30771, 30772, 30927, 30928, 30940, 30941, 371293, 371294, 371306, 371307, 371462
Offset: 0

Views

Author

Keywords

Comments

Numbers without any base-13 digits greater than 1.
a(n) modulo 2 is the Prouhet-Thue-Morse sequence A010060. - Philippe Deléham, Oct 17 2011

Crossrefs

Row 12 of array A104257.

Programs

  • Mathematica
    With[{k = 13}, Map[FromDigits[#, k] &, Tuples[{0, 1}, 6]]] (* Michael De Vlieger, Oct 28 2022 *)
  • PARI
    A033049(n,b=13)=subst(Pol(binary(n)),'x,b) \\ M. F. Hasler, Feb 01 2016

Formula

a(n) = Sum_{i=0..m} d(i)*13^i, where Sum_{i=0..m} d(i)*2^i is the base-2 representation of n.
a(n) = A097259(n)/12.
a(2n) = 13*a(n), a(2n+1) = a(2n)+1.
a(n) = Sum_{k>=0} A030308(n,k)*13^k. - Philippe Deléham, Oct 17 2011
G.f.: (1/(1 - x))*Sum_{k>=0} 13^k*x^(2^k)/(1 + x^(2^k)). - Ilya Gutkovskiy, Jun 04 2017

Extensions

Extended by Ray Chandler, Aug 03 2004

A033051 Numbers whose set of base 15 digits is {0,1}.

Original entry on oeis.org

0, 1, 15, 16, 225, 226, 240, 241, 3375, 3376, 3390, 3391, 3600, 3601, 3615, 3616, 50625, 50626, 50640, 50641, 50850, 50851, 50865, 50866, 54000, 54001, 54015, 54016, 54225, 54226, 54240, 54241, 759375, 759376, 759390, 759391, 759600
Offset: 0

Views

Author

Keywords

Comments

Sums of distinct powers of 15.
a(n) modulo 2 is the Prouhet-Thue-Morse sequence A010060. - Philippe Deléham, Oct 17 2011.

Crossrefs

Row 14 of array A104257.

Programs

  • Mathematica
    With[{k = 15}, Map[FromDigits[#, k] &, Tuples[{0, 1}, 6]]] (* Michael De Vlieger, Oct 28 2022 *)
    FromDigits[#,15]&/@Tuples[{0,1},6] (* Harvey P. Dale, Sep 15 2024 *)
  • PARI
    A033051(n, b=15)=subst(Pol(binary(n)),'x,b) \\ M. F. Hasler, Feb 01 2016

Formula

a(n) = Sum_{i=0..m} d(i)*15^i, where Sum_{i=0..m} d(i)*2^i is the base-2 representation of n.
a(n) = A097261(n)/14.
a(2n) = 15*a(n), a(2n+1) = a(2n)+1.
a(n) = Sum_{k>=0} A030308(n,k)*15^k. - Philippe Deléham, Oct 17 2011.
G.f.: (1/(1 - x))*Sum_{k>=0} 15^k*x^(2^k)/(1 + x^(2^k)). - Ilya Gutkovskiy, Jun 04 2017

Extensions

Extended by Ray Chandler, Aug 03 2004

A033050 Numbers whose set of base 14 digits is {0,1}.

Original entry on oeis.org

0, 1, 14, 15, 196, 197, 210, 211, 2744, 2745, 2758, 2759, 2940, 2941, 2954, 2955, 38416, 38417, 38430, 38431, 38612, 38613, 38626, 38627, 41160, 41161, 41174, 41175, 41356, 41357, 41370, 41371, 537824, 537825, 537838, 537839, 538020
Offset: 0

Views

Author

Keywords

Comments

Sums of distinct powers of 14.
The base-14 digits may comprise zero, one, or both. - Harvey P. Dale, May 12 2014

Crossrefs

Row 13 of array A104257.

Programs

  • Mathematica
    Select[Range[0,540000],Max[IntegerDigits[#,14]]<2&] (* Harvey P. Dale, May 12 2014 *)
    FromDigits[#,14]&/@Tuples[{0,1},6] (* Harvey P. Dale, Jun 18 2021 *)
  • PARI
    A033050(n,b=14)=subst(Pol(binary(n)),'x,b) \\ M. F. Hasler, Feb 01 2016

Formula

a(n) = Sum_{i=0..m} d(i)*14^i, where Sum_{i=0..m} d(i)*2^i is the base-2 representation of n.
a(n) = A097260(n)/13.
a(2n) = 14*a(n), a(2n+1) = a(2n)+1.
a(n) = Sum_{k>=0} A030308(n,k)*14^k. - Philippe Deléham, Oct 20 2011
G.f.: (1/(1 - x))*Sum_{k>=0} 14^k*x^(2^k)/(1 + x^(2^k)). - Ilya Gutkovskiy, Jun 04 2017

Extensions

Extended by Ray Chandler, Aug 03 2004

A197351 a(0)=0, a(1)=1, a(2n)=17*a(n), a(2n+1)=a(2n)+1.

Original entry on oeis.org

0, 1, 17, 18, 289, 290, 306, 307, 4913, 4914, 4930, 4931, 5202, 5203, 5219, 5220, 83521, 83522, 83538, 83539, 83810, 83811, 83827, 83828, 88434, 88435, 88451, 88452, 88723, 88724, 88740, 88741, 1419857, 1419858, 1419874, 1419875
Offset: 0

Views

Author

Philippe Deléham, Oct 14 2011

Keywords

Comments

Numbers whose set of base 17 digits is {0,1}.
Sums of distinct powers of 17.
a(n) modulo 2 is the Prouhet-Thue-Morse sequence A010060. - Philippe Deléham, Oct 17 2011.

Crossrefs

Programs

  • Magma
    [n: n in [0..1500000] | Set(IntegerToSequence(n, 17)) subset {0, 1}]; // Vincenzo Librandi, Jun 05 2012
  • Mathematica
    Take[Union[Total/@Subsets[17^Range[0,20],5]],40] (* Harvey P. Dale, Dec 17 2011 *)
    FromDigits[#,17]&/@Tuples[{0,1},5] (* Vincenzo Librandi, Jun 05 2012 *)

Formula

a(n)=Sum_k>=0 {A030308(n,k)*17^k}.
G.f.: (1/(1 - x))*Sum_{k>=0} 17^k*x^(2^k)/(1 + x^(2^k)). - Ilya Gutkovskiy, Jun 04 2017

A197352 a(0)=0, a(1)=1, a(2n)=18*a(n), a(2n+1)=a(2n)+1.

Original entry on oeis.org

0, 1, 18, 19, 324, 325, 342, 343, 5832, 5833, 5850, 5851, 6156, 6157, 6174, 6175, 104976, 104977, 104994, 104995, 105300, 105301, 105318, 105319, 110808, 110809, 110826, 110827, 111132, 111133, 111150, 111151, 1889568, 1889569, 1889586, 1889587
Offset: 0

Views

Author

Philippe Deléham, Oct 14 2011

Keywords

Comments

Numbers whose set of base 18 digits is {0,1}.
Sums of distinct powers of 18.

Crossrefs

Programs

  • Magma
    [n: n in [0..2000000] | Set(IntegerToSequence(n, 18)) subset {0, 1}]; // Vincenzo Librandi, Jun 05 2012
  • Mathematica
    FromDigits[#,18]&/@Tuples[{0,1},5] (* Vincenzo Librandi, Jun 05 2012 *)

Formula

a(n) = Sum_{k>=0} A030308(n,k)*18^k.
G.f.: (1/(1 - x))*Sum_{k>=0} 18^k*x^(2^k)/(1 + x^(2^k)). - Ilya Gutkovskiy, Jun 04 2017

A197353 a(0)=0, a(1)=1, a(2n)=19*a(n), a(2n+1)=a(2n)+1.

Original entry on oeis.org

0, 1, 19, 20, 361, 362, 380, 381, 6859, 6860, 6878, 6879, 7220, 7221, 7239, 7240, 130321, 130322, 130340, 130341, 130682, 130683, 130701, 130702, 137180, 137181, 137199, 137200, 137541, 137542, 137560, 137561, 2476099, 2476100, 2476118, 2476119
Offset: 0

Views

Author

Philippe Deléham, Oct 14 2011

Keywords

Comments

Numbers whose set of base 19 digits is {0,1}.
Sums of distinct powers of 19.
a(n) modulo 2 is the Prouhet-Thue-Morse sequence A010060. - Philippe Deléham, Oct 17 2011

Crossrefs

Programs

  • Magma
    [n: n in [0..2500000] | Set(IntegerToSequence(n, 19)) subset {0, 1}]; // Vincenzo Librandi, Jun 05 2012
  • Mathematica
    FromDigits[#,19]&/@Tuples[{0,1},5] (* Vincenzo Librandi, Jun 05 2012 *)

Formula

a(n) = Sum_{k>=0} A030308(n,k)*19^k.
G.f.: (1/(1 - x))*Sum_{k>=0} 19^k*x^(2^k)/(1 + x^(2^k)). - Ilya Gutkovskiy, Jun 04 2017

A356274 a(n) is the number whose base-(n+1) expansion equals the binary expansion of n.

Original entry on oeis.org

1, 3, 5, 25, 37, 56, 73, 729, 1001, 1342, 1741, 2366, 2941, 3615, 4369, 83521, 104977, 130340, 160021, 194922, 234741, 280393, 332377, 406250, 474553, 551151, 636637, 732511, 837901, 954304, 1082401, 39135393, 45435425, 52521910, 60466213, 69345326, 79236613
Offset: 1

Views

Author

Thomas Scheuerle, Aug 02 2022

Keywords

Comments

If the binary expansion of n is n = bit0*2^0 + bit1*2^1 + bit2*2^2 + ... then a(n) = bit0*(n+1)^0 + bit1*(n+1)^1 + bit2*(n+1)^2 + ... . In other words: Interpret the binary expansion of n as digits in base n+1.

Examples

			n=4 in binary is 100 and interpreting those digits as base n+1 = 5 is a(4) = 25.
		

Crossrefs

Programs

  • Mathematica
    a[n_] := FromDigits[IntegerDigits[n, 2], n + 1]; Array[a, 40] (* Amiram Eldar, Aug 19 2022 *)
  • PARI
    a(n) = fromdigits(digits(n, 2), n+1)
    
  • Python
    def a(n): return sum((n+1)**i*int(bi) for i, bi in enumerate(bin(n)[2:][::-1]))
    print([a(n) for n in range(1, 39)]) # Michael S. Branicky, Aug 02 2022

Formula

a(2^n) = (2^n + 1)^n = A136516(n).
a(2^n - 1) = (2^(n^2) - 1)/(2^n - 1) = A128889(n).
a(2^n + 1) = 1 + (2^n + 2)^n.
a(n) = A104257(n+1, n).
a(n) = (1/n)*Sum_{j>=1} floor((n + 2^(j-1))/2^j) * ((n-1)*(n+1)^(j-1) + 1).
a(n) = (1/n)*Sum_{j=1..n} ((n-1)*(n+1)^A007814(j) + 1).
a(2*n) = A104258(2*n+1) - 1.
(2*m+1)^n divides a((2*m+1)^n-1) for positive m and n > 0.
Previous Showing 11-18 of 18 results.