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 1-2 of 2 results.

A051735 Binomial coefficients C(n,k) such that C(n,k)-1 and C(n,k)+1 are twin primes and 2<=k<=floor(n/2).

Original entry on oeis.org

6, 462, 1877405874732108, 38650751381832, 10000119226331142599460, 51913710643776705684835560, 42552226353687619569660660, 1656627950725900171898183550, 315676747963758694790502389846048040560005901701920, 3571770735028382091998706667681023581492775768
Offset: 0

Views

Author

Joe DeMaio (jdemaio(AT)kennesaw.edu), Dec 06 1999

Keywords

Comments

Sequence is ordered by size of n not size of C(n,k). Link gives list of all values up to n=1352.

Examples

			C(11,5)=462 is a member of the sequence because 461 and 463 are twin primes.
		

Crossrefs

See A051770 for values of n, A051771 for values of k.

Programs

  • Mathematica
    Select[Flatten[Table[Binomial[n,k],{n,200},{k,2,Floor[n/2]}]], AllTrue[ #+ {1,-1},PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Dec 10 2015 *)

Extensions

More terms from Harvey P. Dale, Dec 10 2015

A051771 Values of k such that there exists a binomial coefficient C(n,k) where C(n,k)-1 and C(n,k)+1 are twin primes and 2<=k<=floor(n/2).

Original entry on oeis.org

2, 5, 26, 13, 35, 44, 37, 23, 78, 46, 34, 69, 44, 106, 41, 50, 90, 89, 132, 107, 137, 143, 184, 145, 133, 166, 181, 82, 158, 198, 157, 175, 183, 163, 317, 293, 140, 123, 317, 251, 218, 169, 170, 103, 327, 229, 329, 73, 190, 79, 51, 95, 79, 290, 395, 432, 126
Offset: 0

Views

Author

Joe DeMaio (jdemaio(AT)kennesaw.edu), Dec 08 1999

Keywords

Comments

This sequence is ordered by the size of the corresponding value of n.

Examples

			The integer 5 is a member of the sequence because C(11,5)=462 and 461 and 463 are twin primes.
		

Crossrefs

Showing 1-2 of 2 results.