

A057602


a(1)=2, a(n+1) is the smallest integer > a(n) such that the smallest prime factor of a(n+1) is the largest prime factor of a(n).


3



2, 4, 6, 9, 15, 25, 35, 49, 77, 121, 143, 169, 221, 289, 323, 361, 437, 529, 667, 841, 899, 961, 1147, 1369, 1517, 1681, 1763, 1849, 2021, 2209, 2491, 2809, 3127, 3481, 3599, 3721, 4087, 4489, 4757, 5041, 5183, 5329, 5767, 6241, 6557, 6889, 7387, 7921
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OFFSET

1,1


LINKS



FORMULA

Even numbered terms are squares of successive primes. Odd numbered terms are the product of two successive primes and are the square root of the product of the previous term and the next term  Jud McCranie, Oct 07 2000


MATHEMATICA

Module[{nn=30, pr, ev, od}, pr=Prime[Range[nn]]; ev=pr^2; od=Times @@@ Partition[ pr, 2, 1]; Join[{2}, Riffle[ev, od]]] (* Harvey P. Dale, Mar 02 2015 *)


CROSSREFS



KEYWORD

nonn


AUTHOR



EXTENSIONS



STATUS

approved



