login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A254787
a(n)= least initial term of n consecutive primes {p(m),..,p(m+n-1)} such that all numbers {1+p(m),..,1+p(m+n-1)} are a product of the same number k primes, where p(m) is m-th prime A000040(m).
1
2, 3, 139, 557, 3821, 53609, 179659, 7190917, 3599100, 16687573, 20394197, 101439558
OFFSET
1,1
COMMENTS
Corresponding values of m are: 1,2,34,102,530,5462,16309,488739,3599100,308495917,20394197,101439558
Corresponding values of k are: 1,2,4,4,5,4,5,4,5,4,5,5
A023514(i=m,..,m+n-1) are of the same value.
EXAMPLE
a(2)=3, because {p(2),p(3)}={3,5}, and {4,6}={2^2,2*3}, k=2;
a(3)=139, because {p(34),p(35),p(36)}={139,149,151}, and {140,150,152}={2^2*5*7,2*3*5^2,2^3*19}, k=4.
CROSSREFS
Sequence in context: A066908 A057738 A234999 * A042073 A124236 A371272
KEYWORD
nonn
AUTHOR
Zak Seidov, Feb 15 2015
STATUS
approved