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.

Showing 1-10 of 10 results.

A126627 a(n) is the number of nonnegative integers k less than 10^n such that the decimal representation of k lacks digits 1,2,3 and at least one of digits 4,5,6,7,8,9.

Original entry on oeis.org

7, 49, 343, 2401, 16807, 116929, 803383, 5432161, 36120007, 236404609, 1525601623, 9726181921, 61371928807, 383929313089, 2384606035063, 14723095123681, 90457525939207, 553507860826369, 3375536272503703, 20528377102849441, 124556950506727207
Offset: 1

Views

Author

Aleksandar M. Janjic and Milan Janjic, Feb 08 2007

Keywords

Crossrefs

Programs

  • Maple
    f:=n->6*6^n-15*5^n+20*4^n-15*3^n+6*2^n-1;
  • Mathematica
    LinearRecurrence[{21,-175,735,-1624,1764,-720},{7,49,343,2401,16807,116929},30] (* Harvey P. Dale, Aug 02 2017 *)
  • PARI
    vector(100, n, 6*6^n-15*5^n+20*4^n-15*3^n+6*2^n-1) \\ Colin Barker, Feb 23 2015

Formula

a(n) = 6*6^n-15*5^n+20*4^n-15*3^n+6*2^n-1.
G.f.: -x*(720*x^5 -1764*x^4 +1372*x^3 -539*x^2 +98*x -7) / ((x -1)*(2*x -1)*(3*x -1)*(4*x -1)*(5*x -1)*(6*x -1)). - Colin Barker, Feb 23 2015

A126628 a(n) is the number of nonnegative integers k less than 10^n such that the decimal representation of k lacks digits 1 and 2, at least one of digits 3,4 and at least one of digits 5,6,7,8,9.

Original entry on oeis.org

8, 62, 470, 3506, 25718, 184682, 1294910, 8867186, 59423078, 390804602, 2529567950, 16157024066, 102070798838, 639011269322, 3970835898590, 24524390352146, 150705922308998, 922285972770842, 5624983337550830, 34210314230099426, 207580309651649558
Offset: 1

Views

Author

Aleksandar M. Janjic and Milan Janjic, Feb 08 2007

Keywords

Crossrefs

Programs

  • Maple
    f:=n->10*6^n-25*5^n+30*4^n-20*3^n+7*2^n-1;
  • Mathematica
    CoefficientList[Series[-2*(360*x^5 - 882*x^4 + 697*x^3 - 284*x^2 + 53*x - 4)/((x - 1)*(2*x - 1)*(3*x - 1)*(4*x - 1)*(5*x - 1)*(6*x - 1)), {x, 0, 30}], x] (* Wesley Ivan Hurt, Jun 22 2022 *)
  • PARI
    vector(100, n, 10*6^n-25*5^n+30*4^n-20*3^n+7*2^n-1) \\ Colin Barker, Feb 23 2015

Formula

a(n) = 10*6^n-25*5^n+30*4^n-20*3^n+7*2^n-1.
G.f.: -2*x*(360*x^5 -882*x^4 +697*x^3 -284*x^2 +53*x -4) / ((x -1)*(2*x -1)*(3*x -1)*(4*x -1)*(5*x -1)*(6*x -1)). - Colin Barker, Feb 23 2015
a(n) = 21*a(n-1)-175*a(n-2)+735*a(n-3)-1624*a(n-4)+1764*a(n-5)-720*a(n-6). - Wesley Ivan Hurt, Jun 22 2022

A126631 a(n) is the number of nonnegative integers k less than 10^n such that the decimal representation of k lacks the digit 1, at least one of digits 2,3, at least one of digits 4,5 and at least one of digits 6,7,8,9.

Original entry on oeis.org

9, 77, 633, 5021, 38409, 283277, 2019033, 13963901, 94144809, 621444077, 4031587833, 25787305181, 163054382409, 1021372934477, 6349128459033, 39222102764861, 241061530639209, 1475385002210477, 8998880800344633, 54732125638998941
Offset: 1

Views

Author

Aleksandar M. Janjic and Milan Janjic, Feb 08 2007

Keywords

Examples

			a(8) = 13963901.
		

Crossrefs

Programs

  • Maple
    f:=n->16*6^n-40*5^n+44*4^n-26*3^n+8*2^n-1;
  • Mathematica
    LinearRecurrence[{21,-175,735,-1624,1764,-720},{9,77,633,5021,38409,283277},30] (* Harvey P. Dale, Oct 14 2016 *)
  • PARI
    Vec(-x*(720*x^5-1764*x^4+1412*x^3-591*x^2+112*x-9)/((x-1)*(2*x-1)*(3*x-1)*(4*x-1)*(5*x-1)*(6*x-1)) + O(x^100)) \\ Colin Barker, Feb 22 2015

Formula

a(n) = 16*6^n-40*5^n+44*4^n-26*3^n+8*2^n-1.
G.f.: -x*(720*x^5-1764*x^4+1412*x^3-591*x^2+112*x-9) / ((x-1)*(2*x-1)*(3*x-1)*(4*x-1)*(5*x-1)*(6*x-1)). - Colin Barker, Feb 22 2015

A126632 a(n) is the number of nonnegative integers k less than 10^n such that the decimal representation of k lacks the digit 1, at least one of digits 2,3, at least one of digits 4,5,6 and at least one of digits 7,8,9.

Original entry on oeis.org

9, 79, 669, 5431, 42189, 314119, 2251629, 15625591, 105563469, 697683559, 4529641389, 28986744151, 183339095949, 1148652643399, 7141191155949, 44118519949111, 271168742599629, 1659705919705639, 10123331198091309, 61571999920648471
Offset: 1

Views

Author

Aleksandar M. Janjic and Milan Janjic, Feb 08 2007

Keywords

Examples

			a(8) = 15625591.
		

Crossrefs

Programs

  • Maple
    f:=n->18*6^n-45*5^n+48*4^n-27*3^n+8*2^n-1;
  • Mathematica
    LinearRecurrence[{21,-175,735,-1624,1764,-720},{9, 79, 669, 5431, 42189, 314119},20] (* James C. McMahon, Dec 26 2024 *)
  • PARI
    Vec(-x*(720*x^5-1764*x^4+1408*x^3-585*x^2+110*x-9) / ((x-1)*(2*x-1)*(3*x-1)*(4*x-1)*(5*x-1)*(6*x-1)) + O(x^100)) \\ Colin Barker, Feb 22 2015

Formula

a(n) = 18*6^n-45*5^n+48*4^n-27*3^n+8*2^n-1.
G.f.: -x*(720*x^5-1764*x^4+1408*x^3-585*x^2+110*x-9) / ((x-1)*(2*x-1)*(3*x-1)*(4*x-1)*(5*x-1)*(6*x-1)). - Colin Barker, Feb 22 2015

A126633 a(n) is the number of nonnegative integers k less than 10^n such that the decimal representation of k lacks at least one of digits 1, 2, at least one of digits 3,4, at least one of digits 5,6 and at least one of digits 7,8,9.

Original entry on oeis.org

10, 94, 832, 6946, 54880, 412714, 2975752, 20722306, 140285200, 928323034, 6031661272, 38617025266, 244322679520, 1531014308554, 9519483716392, 58816232361826, 361524350929840, 2212804949145274, 13497228660885112
Offset: 1

Views

Author

Aleksandar M. Janjic and Milan Janjic, Feb 08 2007

Keywords

Crossrefs

Programs

  • Maple
    A126633:=n->24*6^n-60*5^n+62*4^n-33*3^n+9*2^n-1; seq(A126633(n), n=1..20);
  • Mathematica
    Table[24*6^n - 60*5^n + 62*4^n - 33*3^n + 9*2^n - 1, {n, 20}] (* Wesley Ivan Hurt, May 03 2014 *)
    LinearRecurrence[{21,-175,735,-1624,1764,-720},{10,94,832,6946,54880,412714},30] (* Harvey P. Dale, May 05 2018 *)

Formula

a(n) = 24*6^n-60*5^n+62*4^n-33*3^n+9*2^n-1.
G.f.: -2*x*(360*x^5-882*x^4+713*x^3-304*x^2+58*x-5) / ((x-1)*(2*x-1)*(3*x-1)*(4*x-1)*(5*x-1)*(6*x-1)). - Colin Barker, May 04 2014

A126634 a(n) is the number of nonnegative integers k less than 10^n such that the decimal representation of k lacks the digits 1,2,3,4 and at least one of digits 5,6,7,8,9.

Original entry on oeis.org

6, 36, 216, 1296, 7656, 44136, 248016, 1362096, 7338456, 38927736, 203958816, 1058224896, 5448329256, 27880971336, 141993797616, 720419919696, 3644189320056, 18390164454936, 92630272564416, 465876904526496, 2340309918950856, 11745320884258536
Offset: 1

Views

Author

Aleksandar M. Janjic and Milan Janjic, Feb 08 2007

Keywords

Crossrefs

Programs

  • Maple
    f:=n->5*5^n-10*4^n+10*3^n-5*2^n+1;
  • Mathematica
    LinearRecurrence[{15,-85,225,-274,120},{6,36,216,1296,7656},30] (* Harvey P. Dale, Apr 01 2018 *)
  • PARI
    Vec(-6*x*(20*x^4-39*x^3+31*x^2-9*x+1) / ((x-1)*(2*x-1)*(3*x-1)*(4*x-1)*(5*x-1)) + O(x^100)) \\ Colin Barker, Feb 22 2015

Formula

a(n) = 5*5^n-10*4^n+10*3^n-5*2^n+1.
G.f.: -6*x*(20*x^4-39*x^3+31*x^2-9*x+1) / ((x-1)*(2*x-1)*(3*x-1)*(4*x-1)*(5*x-1)). - Colin Barker, Feb 22 2015

A126635 a(n) is the number of nonnegative integers k less than 10^n such that the decimal representation of k lacks the digits 1,2,3, at least one of digits 4,5 and at least one of digits 6,7,8,9.

Original entry on oeis.org

7, 47, 307, 1943, 11827, 69287, 392707, 2166743, 11703187, 62168327, 325983907, 1692105143, 8714154547, 44600020967, 227161443907, 1152585909143, 5830444893907, 29423488811207, 148206112628707, 745396075770743, 3744474953809267, 18792450661083047
Offset: 1

Views

Author

Aleksandar M. Janjic and Milan Janjic, Feb 08 2007

Keywords

Crossrefs

Programs

  • Maple
    f:=n->8*5^n-16*4^n+14*3^n-6*2^n+1;
  • Mathematica
    LinearRecurrence[{15,-85,225,-274,120},{7,47,307,1943,11827},30] (* Harvey P. Dale, Dec 31 2021 *)
  • PARI
    Vec(-x*(120*x^4-242*x^3+197*x^2-58*x+7) / ((x-1)*(2*x-1)*(3*x-1)*(4*x-1)*(5*x-1)) + O(x^100)) \\ Colin Barker, Feb 22 2015

Formula

a(n) = 8*5^n-16*4^n+14*3^n-6*2^n+1.
G.f.: -x*(120*x^4-242*x^3+197*x^2-58*x+7) / ((x-1)*(2*x-1)*(3*x-1)*(4*x-1)*(5*x-1)). - Colin Barker, Feb 22 2015

A126629 a(n) is the number of nonnegative integers k less than 10^n such that the decimal representation of k lacks digits 1 and 2, at least one of digits 3,4,5 and at least one of digits 6,7,8,9.

Original entry on oeis.org

8, 64, 506, 3916, 29498, 215524, 1527506, 10528876, 70841738, 467044084, 3027621506, 19356463036, 122355512378, 766290978244, 4762898595506, 29420807536396, 180813134269418, 1106606890266004, 6749433735297506, 41050188511748956, 249087606867080858
Offset: 1

Views

Author

Aleksandar M. Janjic and Milan Janjic, Feb 08 2007

Keywords

Crossrefs

Programs

  • Maple
    f:=n->12*6^n-30*5^n+34*4^n-21*3^n+7*2^n-1;
  • Mathematica
    LinearRecurrence[{21,-175,735,-1624,1764,-720},{8,64,506,3916,29498,215524},30] (* Harvey P. Dale, Sep 26 2019 *)
  • PARI
    vector(100, n, 12*6^n-30*5^n+34*4^n-21*3^n+7*2^n-1) \\ Colin Barker, Feb 23 2015

Formula

a(n) = 12*6^n-30*5^n+34*4^n-21*3^n+7*2^n-1.
G.f.: -2*x*(360*x^5 -882*x^4 +695*x^3 -281*x^2 +52*x -4) / ((x -1)*(2*x -1)*(3*x -1)*(4*x -1)*(5*x -1)*(6*x -1)). - Colin Barker, Feb 23 2015

A126718 a(n) is the number of nonnegative integers k less than 10^n such that the decimal representation of k lacks the digits 1,2,3, at least one of digits 4,5, at least one of digits 6,7 and at least one of digits 8,9.

Original entry on oeis.org

7, 43, 235, 1171, 5467, 24403, 105595, 447091, 1864027, 7686163, 31440955, 127865011, 517788187, 2090186323, 8417944315, 33843570931, 135890057947, 545108340883, 2185079263675, 8754257900851, 35058860433307, 140360940805843, 561820285607035
Offset: 1

Views

Author

Aleksandar M. Janjic and Milan Janjic, Feb 13 2007

Keywords

Crossrefs

Programs

  • Magma
    [8*4^n-12*3^n+6*2^n-1: n in [1..30]]; // Vincenzo Librandi, May 31 2011
    
  • Maple
    a:=n->8*4^n-12*3^n+6*2^n-1;
  • Mathematica
    LinearRecurrence[{10,-35,50,-24},{7, 43, 235, 1171},23] (* James C. McMahon, Dec 27 2024 *)
  • PARI
    Vec(-x*(24*x^3-50*x^2+27*x-7) / ((x-1)*(2*x-1)*(3*x-1)*(4*x-1)) + O(x^100)) \\ Colin Barker, Feb 22 2015

Formula

a(n) = 8*4^n - 12*3^n + 6*2^n - 1.
a(n) = 10*a(n-1) - 35*a(n-2) + 50*a(n-3) - 24*a(n-4). - Colin Barker, Feb 22 2015
G.f.: -x*(24*x^3 - 50*x^2 + 27*x - 7) / ((x-1)*(2*x-1)*(3*x-1)*(4*x-1)). - Colin Barker, Feb 22 2015

A258800 The number of zeroless decimal numbers whose digital sum is n.

Original entry on oeis.org

0, 1, 2, 4, 8, 16, 32, 64, 128, 256, 511, 1021, 2040, 4076, 8144, 16272, 32512, 64960, 129792, 259328, 518145, 1035269, 2068498, 4132920, 8257696, 16499120, 32965728, 65866496, 131603200, 262947072, 525375999, 1049716729, 2097364960, 4190597000, 8372936304, 16729373488, 33425781248
Offset: 0

Views

Author

Robert G. Wilson v, Jun 10 2015

Keywords

Comments

If you were to include decimal numbers that contain any number of zeros, then a(n) would be infinity. If on the other hand, you limit the number of zeros to some number, then a(n) is finite.

Examples

			a(0) = 0 since there exists no decimal number lacking a zero whose digital sum is zero.
a(1) = 1 since there exists only one zeroless decimal number whose digital sum is one and that number is 1.
a(2) = 2 since there exist only two zeroless decimal numbers whose digital sum is two and they are 2 & 11.
a(3) = 4 since there exist only four zeroless decimal numbers whose digital sum is three and they are 3, 21, 12 & 111.
a(4) = 8 since there exist only eight zeroless decimal numbers whose digital sum is four and they are 4, 31, 13, 22, 211, 121, 112 & 1111.
		

Crossrefs

Programs

  • Mathematica
    CoefficientList[ Series[-1 + 1/(1 - x (1 + x + x^2) (1 + x^3 + x^6)), {x, 0, 36}], x]

Formula

a(n) = A104144(n+8) for n>0.
G.f.: -(x + x^2 + x^3 + x^4 + x^5 + x^6 + x^7 + x^8 + x^9)/(-1 + x + x^2 + x^3 + x^4 + x^5 + x^6 + x^7 + x^8 + x^9) = -1 + 1/(1-x(1 + x + x^2)(1 + x^3 + x^6)).
Showing 1-10 of 10 results.