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 1-7 of 7 results.

A038029 Incrementally largest values of A038025.

Original entry on oeis.org

1, 4, 9, 10, 12, 21, 22, 24, 25, 27, 35, 38, 45, 49, 58, 64, 65, 72, 77, 80, 82, 87, 95, 104, 105, 123, 129, 133, 145, 161, 169, 170, 203, 209, 218, 225, 235, 244, 249, 261, 286, 289, 309, 335, 339, 340, 341, 369, 388, 398, 418, 437, 440, 448
Offset: 1

Views

Author

Christian G. Bower

Keywords

Crossrefs

Cf. A038030, A038031.

A038027 Least k such that A038025(k)=n-th composite number or 0 if none.

Original entry on oeis.org

5, 184613, 67, 10, 11, 13, 127, 77, 33, 191, 187, 22, 23, 25, 26, 1337, 28, 3909, 504511, 37, 43, 57, 36, 4331, 39, 83, 441
Offset: 1

Views

Author

Christian G. Bower with large values calculated by Fred W. Helenius (fredh(AT)ix.netcom.com)

Keywords

Comments

If there is a k : A038025(k)=42 it is > 6670000.

A038030 Indices of incrementally largest values of A038025.

Original entry on oeis.org

1, 5, 10, 11, 13, 22, 23, 25, 26, 28, 36, 39, 46, 50, 63, 65, 69, 73, 78, 81, 87, 100, 102, 105, 107, 124, 130, 141, 146, 162, 174, 199, 204, 210, 219, 227, 236, 245, 259, 266, 293, 300, 320, 354, 364, 389, 390, 398, 405, 417, 423, 438, 459, 465
Offset: 1

Views

Author

Christian G. Bower

Keywords

Crossrefs

Cf. A038029.

A038032 A038025(n)=1.

Original entry on oeis.org

1, 2, 3, 4, 6, 7, 8, 9, 12, 14, 15, 17, 18, 19, 20, 24, 27, 30, 31, 32, 34, 38, 45, 48, 54, 55, 59, 62, 84, 85, 90, 110, 118, 132, 159, 170, 318, 360, 368, 415, 457, 480, 512, 588, 830, 844, 914, 1468, 1691, 2660, 2932, 3382, 5207, 5227, 10414
Offset: 1

Views

Author

Christian G. Bower

Keywords

A038026 Last position reached by winner of n-th Littlewood Frog Race.

Original entry on oeis.org

2, 3, 7, 5, 19, 7, 29, 17, 19, 19, 43, 13, 103, 29, 31, 41, 103, 19, 191, 41, 67, 43, 137, 73, 149, 103, 109, 83, 317, 31, 311, 97, 181, 103, 191, 71, 439, 191, 233, 89, 379, 67, 463, 113, 181, 137, 967, 97, 613, 149, 197, 181, 607, 109, 331, 233
Offset: 1

Views

Author

Christian G. Bower

Keywords

Comments

Related to Linnik's theorem; main sequence is A085420. - Charles R Greathouse IV, Apr 16 2010
a(n) is the smallest prime such that some subset of primes <= a(n) is a reduced residue system modulo n. - Vladimir Shevelev, Feb 19 2013

Examples

			a(6) = 7 since the primes less than or equal to 7, {2, 3, 5, 7}, reduced modulo 6 are {2, 3, 5, 1}.  This contains the reduced residue system modulo 6, which is {1, 5}, and 7 is clearly the smallest such prime. - _Vladimir Shevelev_, Feb 19 2013

Links

Crossrefs

This sequence is a lower bound for the related sequence A085420.
Cf. A038025.

Programs

  • PARI
    a(n)={
my(todo=(1<1,todo=bitnegimply(todo,1<Charles R Greathouse IV, Feb 14 2011
  • PARI
    p(n,b)=while(!isprime(b), b+= n); b
a(n)=my(t=p(n,1));for(b=2,n-1,if(gcd(n,b)==1,t=max(t,p(n,b))));t \\ Charles R Greathouse IV, Sep 08 2012

Formula

Let p(n,b) be the smallest prime in the arithmetic progression k*n+b, with k >= 0. Then a(n) = max(p(n,b)) with 0 < b < n and gcd(b,n) = 1. - Charles R Greathouse IV, Sep 08 2012

A038031 Position reached by frog in A038029. A038026(A038029(n)).

Original entry on oeis.org

2, 19, 19, 43, 103, 43, 137, 149, 103, 83, 71, 233, 137, 149, 373, 389, 479, 1021, 233, 647, 691, 487, 197, 419, 2459, 619, 389, 1543, 1021, 647, 691, 4349, 1019, 419, 4817, 6581, 3067, 2939, 6983, 2389, 8783, 1489, 2549, 2459, 2887, 11621
Offset: 1

Views

Author

Christian G. Bower

Keywords

Crossrefs

Cf. A038025.

A038028 Position reached by frog in A038027 or 0 if none. A038026(A038027(n)).

Original entry on oeis.org

19, 28615021, 1013, 19, 43, 103, 3697, 631, 181, 4793, 3947, 43, 137, 149, 103, 65539, 83, 222841, 91316521, 439, 463, 433, 71, 281551, 233, 1201, 7537
Offset: 1

Views

Author

Christian G. Bower

Keywords

Crossrefs

Cf. A038025.
Showing 1-7 of 7 results.

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