OFFSET

0,1

COMMENTS

In this sequence a(3) and a(5) are primes. Also a(1)+1, a(6)+1 and a(7)+1 are primes. And a(10)-1 is prime. These may at some future time begin three new sequences.

FORMULA

Find the absolute value of second differences of overlapping pairs of values of n

EXAMPLE

a(0)=4432 because the first two values of first differences in A128193 are 140 and 4572. 4572-140=4432, the first second difference.

CROSSREFS

KEYWORD

easy,nonn

AUTHOR

Enoch Haga, Feb 18 2007

STATUS

approved