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.

A286269 The smallest weight possible for a cyclic prime vector of order n.

Original entry on oeis.org

2, 8, 19, 48, 53, 108, 113, 210, 197, 510
Offset: 1

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Author

Dmitry Kamenetsky, May 05 2017

Keywords

Comments

A cyclic prime vector of order n is an array of n distinct primes P = (p_1, p_2, ..., p_n), such that every sum of an odd number of consecutive elements is also prime. Unlike normal prime vectors, here the sums are allowed to span from the end to the start of the array. The weight of the cyclic prime vector is the sum of its elements. For full details see Kamenetsky's paper.

Examples

			The best solution for n=5 is (5, 7, 17, 13, 11) with a weight of 53. This is a cyclic prime vector because all the generated sums are prime: 5+7+17=29, 7+17+13=37, 17+13+11=41, 13+11+5=29, 11+5+7=23, 5+7+17+13+11=53.
		

Crossrefs

Cf. A286263.

A287939 a(n) is the smallest unused odd prime such that (a(1), ..., a(n)) forms a prime vector. a(1)=3, a(2)=5.

Original entry on oeis.org

3, 5, 11, 7, 41, 19, 23, 61, 29, 151, 137, 79, 1013, 14347, 43151, 7873, 82469, 444187, 63680783, 80158627, 531845381, 13726723, 2948038229, 341461831, 5391683657, 4759989589, 45033191681, 3342118271593, 57517957292507, 25358009530039, 2584135512217541, 616856808553033, 21225241347141287, 10855325323825603
Offset: 1

Views

Author

Dmitry Kamenetsky, Jun 03 2017

Keywords

Comments

A prime vector of order n is an array of n distinct primes P = (p_1, p_2, ..., p_n) such that every sum of an odd number of consecutive elements is also prime. The weight of the prime vector is the sum of its elements. For full details see the Kamenetsky paper.
As of June 2017, (a(1), ..., a(34)) is the longest known prime vector. It was found by J. K. Andersen in Rivera's Puzzle 875.
Can this sequence be extended infinitely?

Crossrefs

A287940 a(n) is the first odd prime greater than a(n-1) such that (a(1), ..., a(n)) forms a prime vector. a(1)=3, a(2)=5.

Original entry on oeis.org

3, 5, 11, 13, 29, 31, 47, 61, 71, 409, 2819, 4261, 113819, 124633, 236507, 250693, 501779, 886609, 29089889, 57721663, 157320827, 465327091, 812828249, 1530361321
Offset: 1

Views

Author

Dmitry Kamenetsky, Jun 03 2017

Keywords

Comments

A prime vector of order n is an array of n distinct primes P = (p_1, p_2, ..., p_n) such that every sum of an odd number of consecutive elements is also prime. The weight of the prime vector is the sum of its elements. For full details see the Kamenetsky paper.
a(1)-a(24) were found by Herbert Kociemba.

Crossrefs

Showing 1-3 of 3 results.