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 1-5 of 5 results.

A074928 a(n)>0 such that p(n)*p(n+1)+a(n) is a minimal prime.

Original entry on oeis.org

1, 2, 2, 2, 6, 2, 8, 2, 6, 8, 4, 6, 14, 6, 12, 10, 8, 4, 2, 6, 12, 6, 6, 8, 6, 24, 6, 14, 6, 18, 12, 10, 8, 6, 2, 12, 10, 18, 10, 4, 2, 12, 8, 18, 6, 10, 4, 6, 8, 2, 4, 2, 2, 6, 10, 6, 2, 12, 2, 8, 20, 8, 2, 24, 2, 6, 30, 14, 20, 6, 6, 6, 6, 4, 20, 4, 6, 2, 2, 12, 2, 6, 6, 6, 2, 22, 8, 32, 6, 12
Offset: 1

Views

Author

Zak Seidov, Oct 02 2002

Keywords

Comments

a(n) is even for n > 1. - Seiichi Manyama, Mar 17 2025

Examples

			a(1) = 1 because p(1)*p(2) + 1 = 2*3 + 1 = 7 -> prime

Links

Crossrefs

Cf. A107019, A107057, A107058.

Programs

  • Mathematica
    NextPrime[#]-#&/@Times@@@Partition[Prime[Range[100]],2,1] (* Harvey P. Dale, May 28 2013 *)

A107019 Records in A074928.

Original entry on oeis.org

1, 2, 6, 8, 14, 24, 30, 32, 58, 60, 68, 70, 84, 102
Offset: 1

Views

Author

Zak Seidov, May 10 2005

Keywords

Crossrefs

Cf. A107057: Positions of records in A074928.

A107058 a(n) = smallest number m>0 such that prime(n)*prime(n+1)-m is a prime.

Original entry on oeis.org

1, 2, 4, 4, 4, 10, 6, 4, 6, 12, 18, 6, 4, 4, 14, 6, 6, 8, 6, 4, 18, 4, 18, 4, 6, 4, 18, 6, 16, 4, 4, 8, 6, 4, 16, 18, 2, 10, 12, 18, 18, 22, 6, 10, 4, 6, 2, 22, 6, 4, 6, 6, 34, 8, 2, 18, 6, 26, 24, 30, 6, 12, 6, 16, 30, 10, 8, 6, 22, 6, 8, 4, 2, 8, 18, 26, 10, 4, 12, 30, 10, 12, 4, 24, 6, 6, 6
Offset: 1

Views

Author

Zak Seidov, May 10 2005

Keywords

Comments

a(n) is even for n > 1. - Seiichi Manyama, Mar 17 2025

Links

Crossrefs

Cf. A107059: records in A107058; A106172: positions of records in A107058. Cf. A074928: a(n)>0 such that p(n)*p(n+1)+a(n) is a smallest prime.
Cf. A074928, A107019, A107057, A107059, A106172.

Programs

  • PARI
    a(n) = { my(m=0, v = prime(n)*prime(n+1)); while (! isprime(v-m), m++;); return (m);} \\ Michel Marcus, Apr 19 2013

A106172 Positions of records in A107058.

Original entry on oeis.org

1, 2, 3, 6, 10, 11, 42, 53, 89, 142, 204, 238, 324, 434, 764, 926
Offset: 1

Views

Author

Zak Seidov, May 10 2005

Keywords

Crossrefs

Cf. A074928, A107019, A107057, A107058, A107059.

A107059 Records in A107058.

Original entry on oeis.org

1, 2, 4, 10, 12, 18, 22, 34, 36, 40, 48, 50, 76, 84, 86, 112
Offset: 1

Views

Author

Zak Seidov, May 10 2005

Keywords

Crossrefs

Cf. A106172: positions of records in A107058.
Cf. A074928, A107019, A107057, A107058, A106172.
Showing 1-5 of 5 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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