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 31-40 of 79 results. Next

A086122 Primes of the form (5^k-1)/4.

Original entry on oeis.org

31, 19531, 12207031, 305175781, 177635683940025046467781066894531, 14693679385278593849609206715278070972733319459651094018859396328480215743184089660644531, 35032461608120426773093239582247903282006548546912894293926707097244777067146515037165954709053039550781
Offset: 1

Views

Author

Labos Elemer, Jul 23 2003

Keywords

Comments

Corresponding exponents k are listed in A004061. - Alexander Adamchuk, Jan 23 2007

Crossrefs

Programs

  • Mathematica
    Do[f=(5^n-1)/4;If[PrimeQ[f],Print[{n,f}]],{n,1,1000}] (* Alexander Adamchuk, Jan 23 2007 *)
    Select[(5^Range[300]-1)/4,PrimeQ] (* Harvey P. Dale, Dec 11 2016 *)

Formula

a(n) = (5^A004061(n) - 1)/4 = A003463[ A004061(n) ]. - Alexander Adamchuk, Jan 23 2007
A003464 INTERSECT A000040.

Extensions

More terms from Alexander Adamchuk, Jan 23 2007

A218750 a(n) = (47^n - 1)/46.

Original entry on oeis.org

0, 1, 48, 2257, 106080, 4985761, 234330768, 11013546097, 517636666560, 24328923328321, 1143459396431088, 53742591632261137, 2525901806716273440, 118717384915664851681, 5579717091036248029008, 262246703278703657363377, 12325595054099071896078720
Offset: 0

Views

Author

M. F. Hasler, Nov 04 2012

Keywords

Comments

Partial sums of powers of 47 (A009991).

Crossrefs

Programs

Formula

a(n) = floor(47^n/46).
G.f.: x/(47*x^2-48*x+1) = x/((1-x)*(1-47*x)). [Colin Barker, Nov 06 2012]
a(0)=0, a(n) = 47*a(n-1) + 1. - Vincenzo Librandi, Nov 08 2012
a(n) = 48*a(n-1) - 47*a(n-2). - Wesley Ivan Hurt, Jan 25 2022
E.g.f.: exp(24*x)*sinh(23*x)/23. - Elmo R. Oliveira, Aug 27 2024

A229437 T(n,k)=Number of nXk 0..6 arrays of the sum of the corresponding element, the element to the east and the element to the south in a larger (n+1)X(k+1) 0..2 array.

Original entry on oeis.org

7, 43, 43, 259, 1213, 259, 1555, 31111, 31111, 1555, 9331, 775213, 2985887, 775213, 9331, 55987, 19122559, 262875231, 262875231, 19122559, 55987, 335923, 469959685, 22257074415, 74760946845, 22257074415, 469959685, 335923, 2015539
Offset: 1

Views

Author

R. H. Hardin Sep 23 2013

Keywords

Comments

Table starts
........7............43.................259....................1555
.......43..........1213...............31111..................775213
......259.........31111.............2985887...............262875231
.....1555........775213...........262875231.............74760946845
.....9331......19122559.........22257074415..........19598169849191
....55987.....469959685.......1848069959519........4960640065587845
...335923...11533872679.....151774667013519.....1235565258789975999
..2015539..282921116029...12382804872500671...305000184885228282189
.12093235.6938596265551.1006185589087041647.74877571723905905928727

Examples

			Some solutions for n=2 k=4
..0..2..4..3....3..3..1..0....0..0..2..1....0..2..5..1....3..0..0..2
..3..4..1..0....6..4..3..3....1..2..2..0....1..2..3..4....3..2..0..1
		

Crossrefs

Column 1 is A003464(n+1)

Formula

Empirical for column k:
k=1: a(n) = 7*a(n-1) -6*a(n-2)
k=2: a(n) = 37*a(n-1) -342*a(n-2) +936*a(n-3) -1296*a(n-4)

A218726 a(n) = (23^n - 1)/22.

Original entry on oeis.org

0, 1, 24, 553, 12720, 292561, 6728904, 154764793, 3559590240, 81870575521, 1883023236984, 43309534450633, 996119292364560, 22910743724384881, 526947105660852264, 12119783430199602073, 278755018894590847680, 6411365434575589496641, 147461404995238558422744
Offset: 0

Views

Author

M. F. Hasler, Nov 04 2012

Keywords

Comments

Partial sums of powers of 23, q-integers for q=23: diagonal k=1 in triangle A022187.
Partial sums are in A014909. Also, the sequence is related to A014941 by A014941(n) = n*a(n) - Sum{a(i), i=0..n-1} for n > 0. - Bruno Berselli, Nov 07 2012

Crossrefs

Programs

Formula

From Vincenzo Librandi, Nov 07 2012: (Start)
G.f.: x/((1-x)*(1-23*x)).
a(n) = floor(23^n/22).
a(n) = 24*a(n-1) - 23*a(n-2). (End)
E.g.f.: exp(12*x)*sinh(11*x)/11. - Elmo R. Oliveira, Aug 27 2024

A218732 a(n) = (29^n - 1)/28.

Original entry on oeis.org

0, 1, 30, 871, 25260, 732541, 21243690, 616067011, 17865943320, 518112356281, 15025258332150, 435732491632351, 12636242257338180, 366451025462807221, 10627079738421409410, 308185312414220872891, 8937374060012405313840, 259183847740359754101361
Offset: 0

Views

Author

M. F. Hasler, Nov 04 2012

Keywords

Comments

Partial sums of powers of 29 (A009973).

Crossrefs

Programs

  • Magma
    [n le 2 select n-1 else 30*Self(n-1)-29*Self(n-2): n in [1..20]]; // Vincenzo Librandi, Nov 07 2012
    
  • Mathematica
    LinearRecurrence[{30, -29}, {0, 1}, 30] (* Vincenzo Librandi, Nov 07 2012 *)
  • Maxima
    A218732(n):=(29^n-1)/28$
    makelist(A218732(n),n,0,30); /* Martin Ettl, Nov 07 2012 */
  • PARI
    a(n)=29^n\28
    

Formula

a(n) = floor(29^n/28).
G.f.: x/((1-x)*(1-29*x)). - Vincenzo Librandi, Nov 07 2012
a(n) = 30*a(n-1) - 29*a(n-2). - Vincenzo Librandi, Nov 07 2012
E.g.f.: exp(15*x)*sinh(14*x)/14. - Elmo R. Oliveira, Aug 27 2024

A218733 a(n) = (30^n - 1)/29.

Original entry on oeis.org

0, 1, 31, 931, 27931, 837931, 25137931, 754137931, 22624137931, 678724137931, 20361724137931, 610851724137931, 18325551724137931, 549766551724137931, 16492996551724137931, 494789896551724137931, 14843696896551724137931, 445310906896551724137931, 13359327206896551724137931
Offset: 0

Views

Author

M. F. Hasler, Nov 04 2012

Keywords

Comments

Partial sums of powers of 30 (A009974).

Crossrefs

Programs

Formula

a(n) = floor(30^n/29).
From Vincenzo Librandi, Nov 07 2012: (Start)
G.f.: x/((1-x)*(1-30*x)).
a(n) = 31*a(n-1) - 30*a(n-2). (End)
E.g.f.: exp(x)*(exp(29*x) - 1)/29. - Elmo R. Oliveira, Aug 29 2024

A218740 a(n) = (37^n - 1)/36.

Original entry on oeis.org

0, 1, 38, 1407, 52060, 1926221, 71270178, 2636996587, 97568873720, 3610048327641, 133571788122718, 4942156160540567, 182859777940000980, 6765811783780036261, 250335035999861341658, 9262396331994869641347, 342708664283810176729840, 12680220578500976539004081
Offset: 0

Views

Author

M. F. Hasler, Nov 04 2012

Keywords

Comments

Partial sums of powers of 37 (A009981).

Crossrefs

Programs

Formula

From Vincenzo Librandi, Nov 07 2012: (Start)
G.f.: x/((1 - x)*(1 - 37*x)).
a(n) = 38*a(n-1) - 37*a(n-2).
a(n) = floor(37^n/36). (End)
E.g.f.: exp(x)*(exp(36*x) - 1)/36. - Stefano Spezia, Mar 28 2023

A218744 a(n) = (41^n - 1)/40.

Original entry on oeis.org

0, 1, 42, 1723, 70644, 2896405, 118752606, 4868856847, 199623130728, 8184548359849, 335566482753810, 13758225792906211, 564087257509154652, 23127577557875340733, 948230679872888970054, 38877457874788447772215, 1593975772866326358660816, 65353006687519380705093457
Offset: 0

Views

Author

M. F. Hasler, Nov 04 2012

Keywords

Comments

Partial sums of powers of 41 (A009985).

Crossrefs

Programs

Formula

a(n) = floor(41^n/40).
G.f.: x/((1-x)*(1-41*x)). - Vincenzo Librandi, Nov 07 2012
a(n) = 42*a(n-1) - 41*a(n-2). - Vincenzo Librandi, Nov 07 2012
E.g.f.: exp(21*x)*sinh(20*x)/20. - Elmo R. Oliveira, Aug 27 2024

A218746 a(n) = (43^n - 1)/42.

Original entry on oeis.org

0, 1, 44, 1893, 81400, 3500201, 150508644, 6471871693, 278290482800, 11966490760401, 514559102697244, 22126041415981493, 951419780887204200, 40911050578149780601, 1759175174860440565844, 75644532518998944331293, 3252714898316954606245600, 139866740627629048068560801
Offset: 0

Views

Author

M. F. Hasler, Nov 04 2012

Keywords

Comments

Partial sums of powers of 43 (A009987).
0 followed by the binomial transform of A170762. - R. J. Mathar, Jul 18 2015

Crossrefs

Programs

Formula

G.f.: x/((1-x)*(1-43*x)). - Vincenzo Librandi, Nov 07 2012
a(n) = 44*a(n-1) - 43*a(n-2). - Vincenzo Librandi, Nov 07 2012
a(n) = floor(43^n/42). - Vincenzo Librandi, Nov 07 2012
E.g.f.: exp(22*x)*sinh(21*x)/21. - Elmo R. Oliveira, Aug 27 2024

A353145 Decimal repunits written in base 6.

Original entry on oeis.org

0, 1, 15, 303, 5051, 123235, 2214223, 35452011, 1034052155, 15005255143, 302130544531, 5034313401115, 123013240420103, 2210234251121451, 35344212440150035, 1032151423443021023, 14535045221530334411, 301223205551110014555
Offset: 0

Views

Author

Seiichi Manyama, Apr 26 2022

Keywords

Crossrefs

Programs

  • PARI
    a(n) = fromdigits(digits((10^n-1)/9, 6));

Formula

a(n) = A007092(A002275(n)).
Previous Showing 31-40 of 79 results. Next