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.

A099826 Sum of the first 3^n primes.

Original entry on oeis.org

2, 10, 100, 1264, 15116, 171148, 1864190, 19697700, 203534530, 2067129306, 20706364528, 205144046742, 2014349179358, 19632546354498, 190150622868298, 1831906588192414, 17567504017456404, 167794196312059488, 1597037992049539274
Offset: 0

Views

Author

Robert G. Wilson v, Oct 25 2004

Keywords

Crossrefs

Programs

  • Mathematica
    NextPrim[n_] := Block[{k = n + 1}, While[ !PrimeQ[k], k++ ]; k]; k = p = 1; s = 0; Do[ While[p = NextPrim[p]; s = s + p; k < 10^n, k++ ]; k++; Print[s], {n, 0, 16}]

Formula

a(n) = A007504(A000244(n)). - Amiram Eldar, Jul 01 2024

Extensions

More terms from Cino Hilliard, Jan 14 2006

A135371 a(n) = prime(3^(n + 1)) - prime(3^n).

Original entry on oeis.org

3, 18, 80, 316, 1124, 3976, 13770, 46398, 155174, 512700, 1679218, 5454768, 17617664, 56578816, 180896064, 576041630, 1827788446, 5781493590, 18236550884, 57379347420, 180130119286, 564319058202, 1764618506934, 5508483994106, 17168384214168, 53431296170784
Offset: 0

Views

Author

Marvin Ray Burns, Dec 09 2007

Keywords

Crossrefs

Programs

  • Mathematica
    Table[Prime[3^(n + 1)] - Prime[3^n], {n, 0, 26}]
  • PARI
    a(n) = prime(3^(n + 1)) - prime(3^n); \\ Michel Marcus, Nov 15 2020

Formula

a(n) = A038833(n+1) - A038833(n). - Jinyuan Wang, Nov 14 2020

Extensions

a(23)-a(25) from Jinyuan Wang, Nov 14 2020

A105462 The 3^n-th irregular prime.

Original entry on oeis.org

37, 67, 233, 467, 1307, 4637, 15601, 54437, 184279, 616391, 2009011, 6568151, 21341821, 68826689, 220682383, 704456869
Offset: 1

Views

Author

Robert G. Wilson v, Apr 07 2005

Keywords

Crossrefs

Programs

  • Mathematica
    ip={ the list of irregular primes to 12 million }; Table[ ip[[3^n]], {n, 0, 11}]

Extensions

a(12) corrected and a(13)-a(17) added by Amiram Eldar, Mar 05 2019

A105467 Number of irregular primes less than or equal to the 3^n-th prime.

Original entry on oeis.org

0, 0, 5, 22, 91, 286, 863, 2577, 7717, 23160, 69939, 209485, 627826, 1881554, 5645226, 16936048
Offset: 1

Views

Author

Robert G. Wilson v, Apr 07 2005

Keywords

Comments

Limit_{n->inf.} a(n)/3^n = 1-e^(-1/2).

Crossrefs

Programs

  • Mathematica
    ip={ the list of irregular primes to 12 million }; Table[ Length[ Select[ip, # < Prime[3^n] &]], {n, 9}]

Extensions

Terms corrected and a(10)-a(16) added by Amiram Eldar, Mar 05 2019

A074382 Difference between (1+3^n)-th and (3^n)-th primes.

Original entry on oeis.org

1, 2, 6, 4, 2, 6, 2, 12, 12, 12, 30, 18, 24, 10, 14, 32, 22, 12, 14, 10, 6, 12, 30, 44, 40, 54, 28, 8, 24, 26, 6, 8, 28, 48, 12, 158, 20
Offset: 0

Views

Author

Labos Elemer, Aug 22 2002

Keywords

Examples

			n=25: a(25)=54 because the 847288609443rd prime is 25270000074757 and the 847288609444th prime is 25270000074811.
		

Crossrefs

Programs

  • Mathematica
    NextPrime[#]-#&/@Table[Prime[3^n],{n,25}] (* Harvey P. Dale, Sep 29 2015 *)

Formula

a(n) = prime(1+3^n) - prime(3^n).

Extensions

Corrected by Harvey P. Dale, Sep 29 2015
a(0), a(26)-a(36) from Chai Wah Wu, Aug 30 2019

A074383 Difference between (1+10^n)-th and (10^n)-th primes.

Original entry on oeis.org

1, 2, 6, 8, 14, 12, 4, 18, 8, 24, 6, 42, 18, 48, 60, 52, 48, 8, 22, 20, 60, 38, 54, 48, 58
Offset: 0

Views

Author

Labos Elemer, Aug 22 2002

Keywords

Examples

			a(18)=22 because the (10^18)th prime is 44211790234832169331, the (1+10^18)th prime is 44211790234832169353.
		

Crossrefs

Formula

a(n) = prime(1+10^n) - prime(10^n).
a(n) = A151800(A006988(n)) - A006988(n).

Extensions

a(19) from Max Alekseyev, May 08 2009
a(20)-a(22) from Max Alekseyev, Dec 04 2014
a(23)-a(24) from Chai Wah Wu using the terms in A006988, Sep 18 2018

A095120 a(n) = prime(3^n - 1).

Original entry on oeis.org

3, 19, 101, 409, 1531, 5507, 19273, 65677, 220859, 733559, 2412763, 7867543, 25485179, 82064011, 262960069, 839001707, 2666790157, 8448283721, 26684834629, 84064182049, 264194301341, 828513359543, 2593131866471, 8101615860581, 25270000074743
Offset: 1

Views

Author

Cino Hilliard, Jun 19 2004

Keywords

Crossrefs

Programs

  • Mathematica
    Prime[3^Range[25]-1] (* Harvey P. Dale, Dec 01 2018 *)
  • PARI
    f(n) = for(x=1,n,print1(prime(3^x-1)","))

Formula

a(n) = A151799(A038833(n)). - Amiram Eldar, Jul 01 2024

Extensions

More terms from Harvey P. Dale, Dec 01 2018

A347000 The (m^n)-th prime, written as square array T(n,m) read by falling antidiagonals.

Original entry on oeis.org

2, 3, 2, 5, 7, 2, 7, 23, 19, 2, 11, 53, 103, 53, 2, 13, 97, 311, 419, 131, 2, 17, 151, 691, 1619, 1543, 311, 2, 19, 227, 1321, 4637, 8161, 5519, 719, 2, 23, 311, 2309, 10627, 28687, 38873, 19289, 1619, 2, 29, 419, 3671, 21391, 79349, 171529, 180503, 65687, 3671, 2
Offset: 1

Views

Author

Hugo Pfoertner, Aug 10 2021

Keywords

Examples

			The array begins
  2   3     5      7     11      13       17 ...
  2   7    23     53     97     151      227 ...
  2  19   103    311    691    1321     2309 ...
  2  53   419   1619   4637   10627    21391 ...
  2 131  1543   8161  28687   79349   185707 ...
  2 311  5519  38873 171529  567871  1549817 ...
  2 719 19289 180503 994837 3950183 12579617 ...
		

Crossrefs

Programs

  • Mathematica
    T[n_,m_]:=Prime[m^n];Flatten[Table[Reverse[Table[T[n-m+1,m],{m,n}]],{n,10}]] (* Stefano Spezia, Aug 10 2021 *)

A096324 a(n) = prime(3^prime(n)).

Original entry on oeis.org

23, 103, 1543, 19289, 2412779, 25485211, 2666790167, 26684834641, 2593131866483, 2358539553316997, 22624672879215149
Offset: 1

Views

Author

Cino Hilliard, Aug 02 2004

Keywords

Examples

			a(1) = prime(3^prime(1)) = prime(3^2) = prime(9) = 23.
		

Crossrefs

Subsequence of A038833.

Programs

Formula

a(n) = A038833(A000040(n)). - Amiram Eldar, Jul 01 2024

Extensions

Edited and extended by Robert G. Wilson v, Aug 07 2004
a(10)-a(11) from Charles R Greathouse IV, Nov 02 2014

A119774 (9^n)-th prime.

Original entry on oeis.org

2, 23, 419, 5519, 65687, 733561, 7867547, 82064027, 839001721, 8448283757, 84064182061, 828513359549, 8101615860589, 78701296245541, 760254097357847, 7308703331126371, 69967771422585271, 667349537482051157, 6344383023407982563
Offset: 0

Views

Author

Jim Snow (jsnow(AT)mitre.org), Jun 22 2006

Keywords

Crossrefs

Cf. A038833.

Programs

Formula

a(n) = A038833(2*n). - Amiram Eldar, Jul 18 2025

Extensions

a(13)-a(18) from Charles R Greathouse IV, Nov 02 2014
Showing 1-10 of 10 results.