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 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 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Harvey P. Dale, Table of n, a(n) for n = 1..1000 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 Cf. A000040. A033476. Sequence in context: A266648 A076922 A157679 * A171646 A074677 A006498 Adjacent sequences: A057599 A057600 A057601 * A057603 A057604 A057605 KEYWORD nonn AUTHOR G. L. Honaker, Jr., Oct 07 2000 EXTENSIONS Additional terms from Jud McCranie, Oct 07 2000 STATUS approved

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Last modified May 24 12:09 EDT 2024. Contains 372773 sequences. (Running on oeis4.)