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 1-3 of 3 results.

A062800 Primes of form 100*k + 1.

Original entry on oeis.org

101, 401, 601, 701, 1201, 1301, 1601, 1801, 1901, 2801, 3001, 3301, 3701, 4001, 4201, 4801, 5101, 5501, 5701, 5801, 6101, 6301, 6701, 7001, 7901, 8101, 8501, 9001, 9601, 9901, 10301, 10501, 10601, 11701, 11801, 12101, 12301, 12401, 12601, 13001, 13901, 14401, 15101
Offset: 1

Views

Author

Jason Earls, Jul 19 2001

Keywords

References

  • W. Dunham, Euler: The Master of Us All, The Mathematical Association of America, Washington, D.C., 1999, p. 78.

Crossrefs

Subsequence of primes of A158128.
Cf. A166457.

Programs

  • Mathematica
    Select[100*Range[200]+1,PrimeQ] (* Harvey P. Dale, May 06 2018 *)
  • PARI
    j=[]; for(n=1,400, if(isprime(100*n+1),j=concat(j,100*n+1))); j
    
  • PARI
    { n=0; for (m=1, 10^9, if (isprime(a=100*m + 1), write("b062800.txt", n++, " ", a); if (n==1000, break)) ) } \\ Harry J. Smith, Aug 11 2009

Formula

a(n) = A158128(A166457(n)). - Elmo R. Oliveira, Feb 22 2025

A158127 a(n) = 100*n^2 + 2*n.

Original entry on oeis.org

102, 404, 906, 1608, 2510, 3612, 4914, 6416, 8118, 10020, 12122, 14424, 16926, 19628, 22530, 25632, 28934, 32436, 36138, 40040, 44142, 48444, 52946, 57648, 62550, 67652, 72954, 78456, 84158, 90060, 96162, 102464, 108966, 115668, 122570
Offset: 1

Views

Author

Vincenzo Librandi, Mar 13 2009

Keywords

Comments

The identity (100*n + 1)^2 - (100*n^2 + 2*n)*10^2 = 1 can be written as A158128(n)^2 - a(n)*10^2 = 1. - Vincenzo Librandi, Feb 11 2012

Crossrefs

Cf. A158128.

Programs

  • Magma
    I:=[102, 404, 906]; [n le 3 select I[n] else 3*Self(n-1)-3*Self(n-2)+1*Self(n-3): n in [1..50]]; // Vincenzo Librandi, Feb 11 2012
    
  • Mathematica
    Table[100n^2 +2n,{n,45}]  (* Harvey P. Dale, Mar 15 2011 *)
    LinearRecurrence[{3, -3, 1}, {102, 404, 906}, 50] (* Vincenzo Librandi, Feb 11 2012 *)
  • PARI
    for(n=1, 50, print1(100*n^2 + 2*n", ")); \\ Vincenzo Librandi, Feb 11 2012

Formula

G.f.: x*(102 + 98*x)/(1-x)^3. - Vincenzo Librandi, Feb 11 2012
a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3). - Vincenzo Librandi, Feb 11 2012

A180469 Primes of the form 100p + 1, where p is prime.

Original entry on oeis.org

701, 1301, 1901, 3701, 6101, 6701, 7901, 10301, 13901, 15101, 16301, 19301, 21101, 22901, 27701, 42101, 46301, 52301, 54101, 60101, 64301, 70901, 72701, 81101, 82301, 87701, 88301, 93701, 102101, 112901, 115301, 117101, 123701, 132701
Offset: 1

Views

Author

Kevin Batista (kevin762401(AT)yahoo.com), Sep 06 2010

Keywords

Examples

			Example: 7*100 + 1 = 701 is prime, and is therefore a term.
		

Crossrefs

Subsequence of A158128.

Programs

  • PARI
    forprime(p=2,1e4,k=100*p+1;if(isprime(k),print1(k",")))
Showing 1-3 of 3 results.