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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A142555 Primes congruent to 25 mod 53.

Original entry on oeis.org

131, 449, 661, 1297, 1721, 1933, 2039, 2251, 2357, 2887, 3947, 4159, 4583, 5113, 5431, 5749, 6067, 6173, 6491, 6703, 7127, 8081, 8293, 8929, 9883, 10837, 11261, 11579, 11897, 12109, 13063, 13381, 13487, 14653, 14759, 15077, 15289, 15607, 16349, 16561, 16879
Offset: 1

Views

Author

N. J. A. Sloane, Jul 11 2008

Keywords

Crossrefs

Programs

Formula

a(n) ~ 52n log n. - Charles R Greathouse IV, Jul 03 2016

A142755 Primes congruent to 28 mod 59.

Original entry on oeis.org

677, 1031, 1621, 2447, 2683, 2801, 3037, 3391, 3863, 4099, 4217, 5279, 5869, 5987, 6577, 7639, 7757, 7993, 8111, 8819, 9173, 10589, 11887, 12241, 12713, 13421, 14011, 15073, 15427, 16253, 16607, 16843, 17551, 17669, 18731, 19793, 20029, 20147, 21563, 21799
Offset: 1

Views

Author

N. J. A. Sloane, Jul 11 2008

Keywords

Crossrefs

Programs

Formula

a(n) ~ 58n log n. - Charles R Greathouse IV, Jul 03 2016

A142827 Primes congruent to 29 mod 61.

Original entry on oeis.org

29, 151, 761, 883, 1249, 1493, 2347, 2591, 2713, 2957, 3079, 3323, 4177, 4421, 4787, 4909, 5153, 5519, 5641, 6007, 6373, 6983, 7349, 8081, 8447, 10399, 11131, 11497, 11863, 12107, 12473, 13327, 13693, 14303, 14669, 15401, 15767, 15889, 16987, 17231, 17597
Offset: 1

Views

Author

N. J. A. Sloane, Jul 11 2008

Keywords

Crossrefs

Programs

  • Magma
    [p: p in PrimesUpTo(18000) | p mod 61 eq 29 ] ; // Vincenzo Librandi, Sep 05 2012
    
  • Mathematica
    Select[Prime[Range[2100]],Mod[#,61]==29&]  (* Harvey P. Dale, Mar 30 2011 *)
    Select[Range[29,18000,61],PrimeQ] (* Harvey P. Dale, Nov 19 2011 *) (* For a larger range of numbers, the second program is faster *)
    Select[Prime[Range[2300]], MemberQ[{29}, Mod[#, 61]] &] (* Vincenzo Librandi, Sep 05 2012 *)
  • PARI
    is(n)=isprime(n) && n%61==29 \\ Charles R Greathouse IV, Jul 03 2016

Formula

a(n) ~ 60n log n. - Charles R Greathouse IV, Jul 03 2016

A154576 a(n) = 2*n^2 + 14*n + 5.

Original entry on oeis.org

21, 41, 65, 93, 125, 161, 201, 245, 293, 345, 401, 461, 525, 593, 665, 741, 821, 905, 993, 1085, 1181, 1281, 1385, 1493, 1605, 1721, 1841, 1965, 2093, 2225, 2361, 2501, 2645, 2793, 2945, 3101, 3261, 3425, 3593, 3765, 3941, 4121, 4305, 4493, 4685, 4881
Offset: 1

Views

Author

Vincenzo Librandi, Jan 12 2009

Keywords

Comments

Seventh diagonal in A144562.
2*a(n) + 39 is a square.

Crossrefs

Programs

  • Magma
    I:=[21, 41, 65]; [n le 3 select I[n] else 3*Self(n-1)-3*Self(n-2)+1*Self(n-3): n in [1..40]]; // Vincenzo Librandi, Feb 22 2012
    
  • Mathematica
    LinearRecurrence[{3, -3, 1}, {21, 41, 65}, 50] (* Vincenzo Librandi, Feb 22 2012 *)
  • PARI
    for(n=1, 40, print1(2*n^2 + 14*n + 5", ")); \\ Vincenzo Librandi, Feb 22 2012

Formula

G.f.: x*(3-x)*(7-5*x)/(1-x)^3. - Bruno Berselli, Dec 07 2011
a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3). - Vincenzo Librandi, Feb 22 2012
Sum_{n>=1} 1/a(n) = 124/1995 + tan(sqrt(39)*Pi/2)*Pi/(2*sqrt(39)). - Amiram Eldar, Feb 25 2023

A154591 a(n) = 2*n^2 + 18*n + 7.

Original entry on oeis.org

27, 51, 79, 111, 147, 187, 231, 279, 331, 387, 447, 511, 579, 651, 727, 807, 891, 979, 1071, 1167, 1267, 1371, 1479, 1591, 1707, 1827, 1951, 2079, 2211, 2347, 2487, 2631, 2779, 2931, 3087, 3247, 3411, 3579, 3751, 3927, 4107, 4291, 4479, 4671, 4867, 5067, 5271
Offset: 1

Views

Author

Vincenzo Librandi, Jan 12 2009

Keywords

Comments

Ninth diagonal of A144562.
2*a(n) + 67 is a square.

Crossrefs

Programs

  • Magma
    I:=[27, 51, 79]; [n le 3 select I[n] else 3*Self(n-1)-3*Self(n-2)+1*Self(n-3): n in [1..40]]; // Vincenzo Librandi, Feb 22 2012
    
  • Mathematica
    LinearRecurrence[{3, -3, 1}, {27, 51, 79}, 50] (* Vincenzo Librandi, Feb 22 2012 *)
  • PARI
    for(n=1, 40, print1(2*n^2 + 18*n + 7", ")); \\ Vincenzo Librandi, Feb 22 2012
    
  • SageMath
    [2*n^2+18*n+7 for n in range(1,51)] #  G. C. Greubel, May 27 2024

Formula

G.f.: (9*x^2-6*x-7)/(x-1)^3. - Bruno Berselli, Dec 07 2011
a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3). - Vincenzo Librandi, Feb 22 2012
Sum_{n>=1} 1/a(n) = 1621/20097 + tan(sqrt(67)*Pi/2)*Pi/(2*sqrt(67)). - Amiram Eldar, Feb 25 2023
E.g.f.: (7 + 20*x + 2*x^2)*exp(x). - G. C. Greubel, May 27 2024

A154600 a(n) = 2*n^2 + 22*n + 9.

Original entry on oeis.org

33, 61, 93, 129, 169, 213, 261, 313, 369, 429, 493, 561, 633, 709, 789, 873, 961, 1053, 1149, 1249, 1353, 1461, 1573, 1689, 1809, 1933, 2061, 2193, 2329, 2469, 2613, 2761, 2913, 3069, 3229, 3393, 3561, 3733, 3909, 4089, 4273, 4461, 4653, 4849, 5049, 5253
Offset: 1

Views

Author

Vincenzo Librandi, Jan 12 2009

Keywords

Comments

Eleventh diagonal of A144562.
2*a(n) + 103 is a square.

Crossrefs

Cf. A144562.

Programs

  • Magma
    I:=[33, 61, 93]; [n le 3 select I[n] else 3*Self(n-1)-3*Self(n-2)+1*Self(n-3): n in [1..40]]; // Vincenzo Librandi, Feb 26 2012
    
  • Mathematica
    LinearRecurrence[{3, -3, 1}, {33, 61, 93}, 50] (* Vincenzo Librandi, Feb 26 2012 *)
    4*Binomial[Range[50]+6,2] - 51 (* G. C. Greubel, May 30 2024 *)
  • PARI
    a(n)=2*n*(n+22)+9 \\ Charles R Greathouse IV, Jan 11 2012
    
  • SageMath
    [2*n^2+22*n+9 for n in range(1,51)] # G. C. Greubel, May 30 2024

Formula

From Vincenzo Librandi, Feb 26 2012: (Start)
G.f: x*(33 - 38*x + 9*x^2)/(1-x)^3.
a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3). (End)
Sum_{n>=1} 1/a(n) = 257162/3084939 + tan(sqrt(103)*Pi/2)*Pi/(2*sqrt(103)). - Amiram Eldar, Feb 25 2023
E.g.f.: -9 + (9 + 24*x + 2*x^2)*exp(x). - G. C. Greubel, May 30 2024

A154628 Primes congruent to 35 mod 73.

Original entry on oeis.org

181, 619, 911, 1787, 1933, 2371, 2663, 3539, 4561, 4999, 5437, 7043, 7481, 7919, 8941, 9817, 11131, 11423, 12007, 13613, 13759, 14051, 14197, 14489, 15073, 15511, 15803, 17117, 18869, 19891, 20183, 21059, 22811, 23687, 23833, 24709, 25147
Offset: 1

Views

Author

Vincenzo Librandi, Jan 17 2009

Keywords

Crossrefs

Programs

Formula

a(n) ~ 72n log n. - Charles R Greathouse IV, Jul 03 2016

A154575 a(n) = 2*n^2 + 12*n + 4.

Original entry on oeis.org

18, 36, 58, 84, 114, 148, 186, 228, 274, 324, 378, 436, 498, 564, 634, 708, 786, 868, 954, 1044, 1138, 1236, 1338, 1444, 1554, 1668, 1786, 1908, 2034, 2164, 2298, 2436, 2578, 2724, 2874, 3028, 3186, 3348, 3514, 3684, 3858, 4036, 4218, 4404, 4594, 4788, 4986, 5188
Offset: 1

Views

Author

Vincenzo Librandi, Jan 12 2009

Keywords

Comments

Sixth diagonal of A144562.
2*a(n) + 28 is a square.

Crossrefs

Programs

  • Magma
    I:=[18, 36, 58]; [n le 3 select I[n] else 3*Self(n-1)-3*Self(n-2)+1*Self(n-3): n in [1..40]]; // Vincenzo Librandi, Feb 26 2012
    
  • Mathematica
    LinearRecurrence[{3, -3, 1}, {18, 36, 58}, 50] (* Vincenzo Librandi, Feb 26 2012 *)
    Table[2n^2+12n+4,{n,50}] (* Harvey P. Dale, Sep 18 2019 *)
  • PARI
    for(n=1, 50, print1(2*n^2+12*n+4", ")); \\ Vincenzo Librandi, Feb 26 2012

Formula

From R. J. Mathar, Jan 05 2011: (Start)
a(n) = 2*A028881(n+3).
G.f.: -2*x*(2*x-3)*(x-3)/(x-1)^3. (End)
a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3). - Vincenzo Librandi, Feb 26 2012
From Amiram Eldar, Feb 25 2023: (Start)
Sum_{n>=1} 1/a(n) = 1/28 - cot(sqrt(7)*Pi)*Pi/(4*sqrt(7)).
Sum_{n>=1} (-1)^(n+1)/a(n) = 31/84 - cosec(sqrt(7)*Pi)*Pi/(4*sqrt(7)). (End)
E.g.f.: 2*exp(x)*(x^2 + 7*x + 2). - Elmo R. Oliveira, Nov 02 2024

A154590 a(n) = 2*n^2 + 16*n + 6.

Original entry on oeis.org

24, 46, 72, 102, 136, 174, 216, 262, 312, 366, 424, 486, 552, 622, 696, 774, 856, 942, 1032, 1126, 1224, 1326, 1432, 1542, 1656, 1774, 1896, 2022, 2152, 2286, 2424, 2566, 2712, 2862, 3016, 3174, 3336, 3502, 3672, 3846, 4024, 4206, 4392, 4582, 4776, 4974, 5176
Offset: 1

Views

Author

Vincenzo Librandi, Jan 12 2009

Keywords

Comments

Eighth diagonal of A144562.
2*a(n) + 52 is a square.

Crossrefs

Programs

  • Mathematica
    Table[2n^2+16n+6,{n,50}] (* or *) LinearRecurrence[{3,-3,1},{24,46,72},50] (* Harvey P. Dale, Dec 27 2011 *)
  • PARI
    a(n)=2*n^2+16*n+6 \\ Charles R Greathouse IV, Jun 17 2017

Formula

a(n) = 2*A116711(n+3).
G.f.: -2*x*(3*x-4)*(x-3)/(x-1)^3.
From Amiram Eldar, Mar 02 2023: (Start)
Sum_{n>=1} 1/a(n) = 35/468 - cot(sqrt(13)*Pi)*Pi/(4*sqrt(13)).
Sum_{n>=1} (-1)^(n+1)/a(n) = 121/468 + cosec(sqrt(13)*Pi)*Pi/(4*sqrt(13)). (End)
From Elmo R. Oliveira, Jun 04 2025: (Start)
E.g.f.: 2*(exp(x)*(x^2 + 9*x + 3) - 3).
a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) for n > 3. (End)

Extensions

Corrected (a(31) added) by Harvey P. Dale, Dec 27 2011

A154599 a(n) = 2*n^2 + 20*n + 8.

Original entry on oeis.org

30, 56, 86, 120, 158, 200, 246, 296, 350, 408, 470, 536, 606, 680, 758, 840, 926, 1016, 1110, 1208, 1310, 1416, 1526, 1640, 1758, 1880, 2006, 2136, 2270, 2408, 2550, 2696, 2846, 3000, 3158, 3320, 3486, 3656, 3830, 4008, 4190, 4376, 4566, 4760, 4958, 5160
Offset: 1

Views

Author

Vincenzo Librandi, Jan 12 2009

Keywords

Comments

Tenth diagonal of A144562.
2*a(n) + 84 is a square.

Crossrefs

Programs

  • Magma
    I:=[30, 56, 86]; [n le 3 select I[n] else 3*Self(n-1)-3*Self(n-2)+1*Self(n-3): n in [1..40]]; // Vincenzo Librandi, Feb 26 2012
    
  • Mathematica
    LinearRecurrence[{3, -3, 1}, {30, 56, 86}, 50] (* Vincenzo Librandi, Feb 26 2012 *)
    Table[2n^2+20n+8,{n,50}] (* Harvey P. Dale, Jun 15 2019 *)
  • PARI
    for(n=1, 40, print1(2*n^2+20*n+8", ")); \\ Vincenzo Librandi, Feb 26 2012
    
  • SageMath
    [2*n^2+20*n+8 for n in range(1,41)] # G. C. Greubel, May 30 2024

Formula

From R. J. Mathar, Jan 05 2011: (Start)
a(n) = 2*A127147(n+13).
G.f.: 2*x*(5-4*x)*(3-x)/(1-x)^3. (End)
From Amiram Eldar, Feb 25 2023: (Start)
Sum_{n>=1} 1/a(n) = 79/952 - cot(sqrt(21)*Pi)*Pi/(4*sqrt(21)).
Sum_{n>=1} (-1)^(n+1)/a(n) = 2851/14280 - cosec(sqrt(21)*Pi)*Pi/(4*sqrt(21)). (End)
E.g.f.: 2*(-4 + (4 + 11*x + x^2)*exp(x)). - G. C. Greubel, May 30 2024
Previous Showing 21-30 of 33 results. Next