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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A103455 a(n) = 0^n + 5^n - 1.

Original entry on oeis.org

1, 4, 24, 124, 624, 3124, 15624, 78124, 390624, 1953124, 9765624, 48828124, 244140624, 1220703124, 6103515624, 30517578124, 152587890624, 762939453124, 3814697265624, 19073486328124, 95367431640624, 476837158203124
Offset: 0

Views

Author

Paul Barry, Feb 06 2005

Keywords

Comments

A transform of 5^n under the matrix A103452.

Crossrefs

Programs

Formula

G.f.: (1 - 2*x + 5*x^2)/((1-x)*(1-5*x)).
a(n) = Sum_{k=0..n} A103452(n, k)*5^k.
a(n) = Sum_{k=0..n} (2*0^(n-k) - 1)*0^(k*(n-k))*5^k.
a(n) = A024049(n), n > 0. - R. J. Mathar, Aug 30 2008
E.g.f.: 1 - exp(x) + exp(5*x). - G. C. Greubel, Jun 21 2021

A137410 a(n) = (5^n - 3)/2.

Original entry on oeis.org

-1, 1, 11, 61, 311, 1561, 7811, 39061, 195311, 976561, 4882811, 24414061, 122070311, 610351561, 3051757811, 15258789061, 76293945311, 381469726561, 1907348632811, 9536743164061, 47683715820311, 238418579101561, 1192092895507811, 5960464477539061, 29802322387695311, 149011611938476561
Offset: 0

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Author

Ctibor O. Zizka, Apr 15 2008

Keywords

Comments

Sequence is a(n) = a(n;5,3,1) where a(n;A,B,r) = (A^n - B^r)/(A - B) for arbitrary integers A, B, r with A != B.
Primes of this form are sometimes of interest, examples:
A=2, B=1, r=1 gives A000225 and subsequence of primes: A001348,
A=3, B=1, r=1 gives A003462 and subsequence of primes: A028491,
A=3, B=2, r=1 gives A058481 and subsequence of primes: A014224,
A=4, B=1, r=1 gives A002450,
A=4, B=2, r=1 gives A083420,
A=4, B=2, r=2 gives A002446,
A=5, B=1, r=1 gives A003463 and subsequence of primes: A004061,
A=5, B=2, r=1 gives A037577.
Sum of n-th row of triangle of powers of 5: 1; 5 1 5; 25 5 1 5 25; 125 25 5 1 5 25 125; ... (cf. Examples). - Philippe Deléham, Feb 24 2014
Integer solutions to x^5 - (x+1)^5 -(x+2)^5 +(x+3)^5 = 5^m + 5^n (see Campbell and Zujev). - Michel Marcus, Mar 02 2016

Examples

			From _Philippe Deléham_, Feb 24 2014: (Start)
a(1) = 1;
a(2) = 5 + 1 + 5 = 11;
a(3) = 25 + 5 + 1 + 5 + 25 = 61;
a(4) = 125 + 25 + 5 + 1 + 5 + 25 + 125 = 311;
etc. (End)
		

Crossrefs

Programs

Formula

a(n) = (5^n - 3)/2.
From Colin Barker, May 01 2012: (Start)
a(n) = 6*a(n-1) - 5*a(n-2).
G.f.: (-1+7*x)/((1-x)*(1-5*x)). (End)
a(n) = 5*a(n-1) + 6, a(1) = 1. - Philippe Deléham, Feb 24 2014
From Elmo R. Oliveira, Dec 11 2023: (Start)
a(n) = A024049(n)/2 - 1 = A125831(n) - 1.
E.g.f.: (1/2)*(exp(5*x) - 3*exp(x)). (End)

Extensions

More terms from Michel Marcus, Mar 02 2016
Edited and missing term a(0) inserted by M. F. Hasler, Jul 10 2018

A249435 a(1) = 0, after which one less than prime powers p^m with exponent m >= 2.

Original entry on oeis.org

0, 3, 7, 8, 15, 24, 26, 31, 48, 63, 80, 120, 124, 127, 168, 242, 255, 288, 342, 360, 511, 528, 624, 728, 840, 960, 1023, 1330, 1368, 1680, 1848, 2047, 2186, 2196, 2208, 2400, 2808, 3124, 3480, 3720, 4095, 4488, 4912, 5040, 5328, 6240, 6560, 6858, 6888, 7920, 8191, 9408, 10200, 10608, 11448
Offset: 1

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Author

Antti Karttunen, Nov 02 2014

Keywords

Crossrefs

One less than A025475.
Subsequence of A181062 and also a subsequence of A249433 (after the initial zero).
Union of sequences A000225, A024023, A024049, A024075, A024127, etc. without their term a(1).
Apart from the first term, subsequence of A045542.

Programs

  • PARI
    list(lim)=my(v=List([0])); lim=lim\1+1; for(m=2,logint(lim,2), forprime(p=2,sqrtnint(lim,m), listput(v, p^m-1))); Set(v) \\ Charles R Greathouse IV, Aug 26 2015
  • Scheme
    (define (A249435 n) (- (A025475 n) 1))
    

Formula

a(n) = A025475(n) - 1.

A114808 The numbers 5^n-1 written in groups of three digits, with leading zeros omitted.

Original entry on oeis.org

424, 124, 624, 312, 415, 624, 781, 243, 906, 241, 953, 124, 976, 562, 448, 828, 124, 244, 140, 624, 122, 70, 312, 461, 35, 156, 243, 51, 757, 812, 415, 258, 789, 62, 476, 293, 945, 312, 438, 146, 972, 656, 241, 907, 348, 632, 812, 495, 367, 431, 640, 624, 476, 837, 158, 203, 124, 238, 418, 579
Offset: 1

Views

Author

Jonathan Vos Post, Feb 19 2006

Keywords

Examples

			4, 24, 124, 624, 3124, 15624, ...
		

Crossrefs

Programs

  • Maple
    L := [] ;
    for n from 1 to 30 do
        dggs := ListTools[Reverse](convert(5^n-1,base,10) );
        L := [op(L),op(dggs)] ;
    end do:
    for k from 1 to nops(L)-3 by 3 do
        op(k,L)*100+op(k+1,L)*10+op(k+2,L) ;
        printf("%d,",%) ;
    end do: # R. J. Mathar, Jun 23 2014
  • Mathematica
    FromDigits[#] & /@ Partition[ Flatten@ IntegerDigits@ Table[5^n - 1, {n, 22}], 3] (* Robert G. Wilson v, Jun 23 2014 *)

Extensions

Definition and terms realigned with A114645 by Robert G. Wilson v, Jun 23 2014

A198762 a(n) = 3*5^n - 1 = 2*A057651(n).

Original entry on oeis.org

2, 14, 74, 374, 1874, 9374, 46874, 234374, 1171874, 5859374, 29296874, 146484374, 732421874, 3662109374, 18310546874, 91552734374, 457763671874, 2288818359374, 11444091796874, 57220458984374, 286102294921874, 1430511474609374, 7152557373046874, 35762786865234374
Offset: 0

Views

Author

Vincenzo Librandi, Oct 30 2011

Keywords

Crossrefs

Programs

  • Magma
    [(3*5^n-1): n in [0..30]];
  • Mathematica
    CoefficientList[Series[2*(1 + x)/(1 - 6*x + 5*x^2), {x, 0, 30}], x] (* Vincenzo Librandi, Jan 04 2013 *)
    LinearRecurrence[{6,-5},{2,14},30] (* Harvey P. Dale, Mar 19 2013 *)

Formula

a(n) = 5*a(n-1) + 4.
a(n) = 6*a(n-1) - 5*a(n-2), n > 1.
G.f.: 2*(1 + x)/(1 - 6*x + 5*x^2). - Vincenzo Librandi, Jan 04 2013
E.g.f.: exp(x)*(3*exp(4*x) - 1). - Elmo R. Oliveira, Mar 29 2025

A198764 6*5^n-1.

Original entry on oeis.org

5, 29, 149, 749, 3749, 18749, 93749, 468749, 2343749, 11718749, 58593749, 292968749, 1464843749, 7324218749, 36621093749, 183105468749, 915527343749, 4577636718749, 22888183593749, 114440917968749, 572204589843749, 2861022949218749
Offset: 0

Views

Author

Vincenzo Librandi, Oct 30 2011

Keywords

Crossrefs

Programs

  • Magma
    [6*5^n-1: n in [0..30]]
  • Mathematica
    CoefficientList[Series[(5 - x)/(1 - 6*x + 5*x^2), {x, 0, 30}], x] (* Vincenzo Librandi, Jan 04 2013 *)
    6*5^Range[0,30]-1 (* or *) LinearRecurrence[{6,-5},{5,29},30] (* Harvey P. Dale, Dec 21 2014 *)

Formula

a(n) = 5*a(n-1)+4.
a(n) = 6*a(n-1)-5*a(n-2), n>1.
G.f.: (5 - x)/(1 - 6*x + 5*x^2). - Vincenzo Librandi, Jan 04 2013

A198763 a(n) = 4*5^n-1.

Original entry on oeis.org

3, 19, 99, 499, 2499, 12499, 62499, 312499, 1562499, 7812499, 39062499, 195312499, 976562499, 4882812499, 24414062499, 122070312499, 610351562499, 3051757812499, 15258789062499, 76293945312499, 381469726562499, 1907348632812499
Offset: 0

Views

Author

Vincenzo Librandi, Oct 30 2011

Keywords

Crossrefs

Programs

  • Magma
    [4*5^n-1: n in [0..30]]
  • Mathematica
    CoefficientList[Series[(3 + x)/(1 - 6*x + 5*x^2), {x, 0, 30}], x] (* Vincenzo Librandi, Jan 04 2013 *)
    NestList[5#+4&,3,30] (* or *) LinearRecurrence[{6,-5},{3,19},30] (* Harvey P. Dale, Jul 03 2021 *)

Formula

a(n) = 5*a(n-1)+4.
a(n) = 6*a(n-1)-5*a(n-2), n>1.
G.f.: (3 + x)/(1 - 6*x + 5*x^2). - Vincenzo Librandi, Jan 04 2013

A198765 7*5^n-1.

Original entry on oeis.org

6, 34, 174, 874, 4374, 21874, 109374, 546874, 2734374, 13671874, 68359374, 341796874, 1708984374, 8544921874, 42724609374, 213623046874, 1068115234374, 5340576171874, 26702880859374, 133514404296874
Offset: 0

Views

Author

Vincenzo Librandi, Oct 30 2011

Keywords

Crossrefs

Programs

  • Magma
    [7*5^n-1: n in [0..30]];
  • Mathematica
    CoefficientList[Series[2*(3 - x)/(1 - 6*x + 5*x^2), {x, 0, 30}], x] (* Vincenzo Librandi, Jan 04 2013 *)
    7 * 5^Range[0, 19] - 1 (* Alonso del Arte, Dec 05 2013 *)

Formula

a(n) = 5*a(n-1) + 4.
a(n) = 6*a(n-1) - 5*a(n-2), n > 1.
G.f.: 2*(3 - x)/(1 - 6*x + 5*x^2). - Vincenzo Librandi, Jan 04 2013

A198766 a(n) = (7*5^n - 1)/2.

Original entry on oeis.org

3, 17, 87, 437, 2187, 10937, 54687, 273437, 1367187, 6835937, 34179687, 170898437, 854492187, 4272460937, 21362304687, 106811523437, 534057617187, 2670288085937, 13351440429687, 66757202148437, 333786010742187, 1668930053710937
Offset: 0

Views

Author

Vincenzo Librandi, Oct 30 2011

Keywords

Crossrefs

Programs

  • Magma
    [(7*5^n-1)/2: n in [0..30]];
  • Mathematica
    CoefficientList[Series[(3 - x)/(1 - 6*x + 5*x^2), {x, 0, 30}], x] (* Vincenzo Librandi, Jan 04 2013 *)
    LinearRecurrence[{6,-5},{3,17},30] (* Harvey P. Dale, Jan 23 2015 *)

Formula

a(n) = 5*a(n-1)+2.
a(n) = 6*a(n-1)-5*a(n-2), n>1.
G.f.: (3 - x)/(1 - 6*x + 5*x^2). - Vincenzo Librandi, Jan 04 2013
E.g.f.: exp(x)*(7*exp(4*x) - 1)/2. - Stefano Spezia, Mar 08 2025

A198767 8*5^n-1.

Original entry on oeis.org

7, 39, 199, 999, 4999, 24999, 124999, 624999, 3124999, 15624999, 78124999, 390624999, 1953124999, 9765624999, 48828124999, 244140624999, 1220703124999, 6103515624999, 30517578124999, 152587890624999, 762939453124999
Offset: 0

Views

Author

Vincenzo Librandi, Oct 30 2011

Keywords

Crossrefs

Programs

  • Magma
    [8*5^n-1: n in [0..30]];
  • Mathematica
    CoefficientList[Series[(7 - 3*x)/(1 - 6*x + 5*x^2), {x, 0, 30}], x] (* Vincenzo Librandi, Jan 04 2013 *)

Formula

a(n) = 5*a(n-1)+4.
a(n) = 6*a(n-1)-5*a(n-2), n>1.
G.f.: (7 - 3*x)/(1 - 6*x + 5*x^2). - Vincenzo Librandi, Jan 04 2013
Previous Showing 21-30 of 36 results. Next