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.

A074118 Largest power of 3 <= 10^n.

Original entry on oeis.org

1, 9, 81, 729, 6561, 59049, 531441, 4782969, 43046721, 387420489, 3486784401, 94143178827, 847288609443, 7625597484987, 68630377364883, 617673396283947, 5559060566555523, 50031545098999707, 450283905890997363
Offset: 0

Views

Author

Amarnath Murthy, Aug 27 2002

Keywords

Comments

a(n)=3^d(n), with d(0)=0 and d(n)=A054965(n) if n>0. [Zak Seidov, Oct 01 2010]

Crossrefs

Programs

  • Mathematica
    Table[3^Floor@Log[3, 10^n],{n,0,20}] (*Zak Seidov, Sep 29 2010*)

Extensions

a(0)=1 and more terms from Zak Seidov, Sep 29 2010

A320862 Powers of 2 with initial digit 6.

Original entry on oeis.org

64, 65536, 67108864, 68719476736, 604462909807314587353088, 618970019642690137449562112, 633825300114114700748351602688, 649037107316853453566312041152512, 664613997892457936451903530140172288, 680564733841876926926749214863536422912
Offset: 1

Views

Author

Muniru A Asiru, Oct 23 2018

Keywords

Crossrefs

Cf. A000079 (powers of 2), A008952 (leading digit of 2^n), A217399 (numbers starting with 6).
Powers of 2 with initial digit k, (k = 1..6): A067488, A067480, A320859, A320860, A320861, this sequence.

Programs

  • GAP
    Filtered(List([0..180],n->2^n),i->ListOfDigits(i)[1]=6);
    
  • Magma
    [2^n: n in [1..160] | Intseq(2^n)[#Intseq(2^n)] eq 6]; // G. C. Greubel, Oct 27 2018
  • Maple
    select(x->"6"=""||x[1],[2^n$n=0..180])[];
  • Mathematica
    Select[2^Range[160], First[IntegerDigits[#]] == 6 &] (* G. C. Greubel, Oct 27 2018 *)
  • PARI
    select(x->(digits(x)[1]==6), vector(200, n, 2^n)) \\ Michel Marcus, Oct 26 2018
    

A067493 Powers of 7 with initial digit 1.

Original entry on oeis.org

1, 16807, 117649, 1977326743, 13841287201, 1628413597910449, 11398895185373143, 191581231380566414401, 1341068619663964900807, 157775382034845806615042743, 1104427674243920646305299201
Offset: 1

Views

Author

Amarnath Murthy, Feb 09 2002

Keywords

Crossrefs

Programs

  • GAP
    Filtered(List([0..40],n->7^n),i->ListOfDigits(i)[1]=1); # Muniru A Asiru, Oct 22 2018

Extensions

Offset 1 by Michel Marcus, Oct 19 2018

A320863 Powers of 2 with initial digit 7.

Original entry on oeis.org

70368744177664, 72057594037927936, 73786976294838206464, 75557863725914323419136, 77371252455336267181195264, 79228162514264337593543950336, 713623846352979940529142984724747568191373312, 730750818665451459101842416358141509827966271488
Offset: 1

Views

Author

Muniru A Asiru, Oct 26 2018

Keywords

Crossrefs

Cf. A000079 (powers of 2), A008952 (leading digit of 2^n), A217400 (numbers starting with 7).
Powers of 2 with initial digit k, (k = 1..7): A067488, A067480, A320859, A320860, A320861, A320862, this sequence.

Programs

  • GAP
    Filtered(List([0..180],n->2^n),i->ListOfDigits(i)[1]=7);
    
  • Magma
    [2^n: n in [1..160] | Intseq(2^n)[#Intseq(2^n)] eq 7]; // G. C. Greubel, Oct 27 2018
  • Maple
    select(x->"7"=""||x[1],[2^n$n=0..180])[];
  • Mathematica
    Select[2^Range[160], First[IntegerDigits[#]] == 7 &] (* G. C. Greubel, Oct 27 2018 *)
  • PARI
    select(x->(digits(x)[1]==7), vector(200, n, 2^n)) \\ Michel Marcus, Oct 27 2018
    

A067494 Powers of 8 with initial digit 1.

Original entry on oeis.org

1, 16777216, 134217728, 1073741824, 18014398509481984, 144115188075855872, 1152921504606846976, 19342813113834066795298816, 154742504910672534362390528, 1237940039285380274899124224
Offset: 1

Views

Author

Amarnath Murthy, Feb 09 2002

Keywords

Crossrefs

Programs

  • GAP
    Filtered(List([0..40],n->8^n),i->ListOfDigits(i)[1]=1); # Muniru A Asiru, Oct 22 2018
  • Mathematica
    Select[8^Range[0,30],IntegerDigits[#][[1]]==1&] (* Harvey P. Dale, Jun 10 2023 *)

Extensions

Offset 1 by Michel Marcus, Oct 19 2018

A320864 Powers of 2 with initial digit 8.

Original entry on oeis.org

8, 8192, 8388608, 8589934592, 8796093022208, 81129638414606681695789005144064, 83076749736557242056487941267521536, 85070591730234615865843651857942052864, 87112285931760246646623899502532662132736, 89202980794122492566142873090593446023921664
Offset: 1

Views

Author

Muniru A Asiru, Nov 21 2018

Keywords

Crossrefs

Cf. A000079 (powers of 2), A008952 (leading digit of 2^n), A217401 (numbers starting with 8).
Powers of 2 with initial digit k, (k = 1..8): A067488, A067480, A320859, A320860, A320861, A320862, A320863, this sequence.

Programs

  • GAP
    Filtered(List([0..200],n->2^n),i->ListOfDigits(i)[1]=8);
    
  • Maple
    select(x->"8"=""||x[1],[2^n$n=0..200])[];
  • Mathematica
    Select[2^Range[200], IntegerDigits[#][[1]] == 8 &] (* Amiram Eldar, Nov 21 2018 *)
  • PARI
    select(x->(digits(x)[1]==8), vector(200, n, 2^n)) \\ Michel Marcus, Nov 21 2018

A067495 Powers of 9 having initial digit 1.

Original entry on oeis.org

1, 1853020188851841, 16677181699666569, 150094635296999121, 1350851717672992089, 12157665459056928801, 109418989131512359209, 1824800363140073127359051977856583921, 16423203268260658146231467800709255289, 147808829414345923316083210206383297601
Offset: 1

Views

Author

Amarnath Murthy, Feb 09 2002

Keywords

Crossrefs

Programs

  • GAP
    Filtered(List([0..40],n->9^n),i->ListOfDigits(i)[1]=1); # Muniru A Asiru, Oct 22 2018
  • Maple
    select(x-> "1"=""||x[1],[9^n$n=0..60])[];  # Alois P. Heinz, Oct 22 2018
  • Mathematica
    Select[9^Range[0,50],First[IntegerDigits[#]]==1&] (* Harvey P. Dale, Oct 01 2015 *)

Extensions

More terms from Harvey P. Dale, Oct 01 2015

A320865 Powers of 2 with initial digit 9.

Original entry on oeis.org

9007199254740992, 9223372036854775808, 9444732965739290427392, 9671406556917033397649408, 9903520314283042199192993792, 91343852333181432387730302044767688728495783936, 93536104789177786765035829293842113257979682750464
Offset: 1

Views

Author

Muniru A Asiru, Nov 21 2018

Keywords

Crossrefs

Cf. A000079 (powers of 2), A008952 (leading digit of 2^n), A217402 (numbers starting with 9).
Powers of 2 with initial digit k, (k = 1..9): A067488, A067480, A320859, A320860, A320861, A320862, A320863, A320864, this sequence.

Programs

  • GAP
    Filtered(List([0..200],n->2^n),i->ListOfDigits(i)[1]=9);
    
  • Maple
    select(x->"9"=""||x[1],[2^n$n=0..200])[];
  • Mathematica
    Select[2^Range[200], IntegerDigits[#][[1]] == 9 &] (* Amiram Eldar, Nov 21 2018 *)
  • PARI
    select(x->(digits(x)[1]==9), vector(200, n, 2^n)) \\ Michel Marcus, Nov 21 2018
Previous Showing 11-18 of 18 results.