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.

A082431 a(n) = the smallest prime p such that there are exactly n sets of consecutive primes, each of which has an arithmetic mean of p.

Original entry on oeis.org

2, 5, 89, 53, 157, 173, 1597, 15233, 8803, 106753, 1570927, 5296771
Offset: 1

Views

Author

Naohiro Nomoto, May 11 2003

Keywords

Examples

			a(4) = 53 because there are exactly four sets of consecutive primes which have means of 53: {53}, {47,53,59}, {41,...,67} and {31,...,73},
		

Crossrefs

Programs

  • PARI
    {a(n)= m=2; starting_index=1; k=starting_index; sum_of_primes=0; prime_count=0; sets=0; until( (prime(starting_index)>m) && (sets==n), if( (prime(starting_index)>m) || (sets>n), m=nextprime(m+1); sets=0; starting_index=1; k=starting_index); sum_of_primes=sum_of_primes+prime(k); prime_count++; mean=sum_of_primes/prime_count; if(meanRick L. Shepherd, Jun 14 2004

Extensions

Edited by Don Reble, Jun 17 2003