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A324594
a(n) is the smallest number k such that n consecutive integers starting at k have the same number of nonprime divisors (A033273).
4
1, 1, 1, 19940, 204323, 294590, 310042685, 2587701932494, 2587701932494
OFFSET
1,4
EXAMPLE
19940 has 9 nonprime divisors {1, 4, 10, 20, 1994, 3988, 4985, 9970, 19940}, 19941 has 9 nonprime divisors {1, 51, 69, 289, 391, 867, 1173, 6647, 19941}, 19942 has 9 nonprime divisors {1, 26, 118, 169, 338, 767, 1534, 9971, 19942} and 19943 has 9 nonprime divisors {1, 49, 77, 259, 407, 539, 1813, 2849, 19943}. These the first 4 consecutive numbers with the same number of nonprime divisors, so a(4) = 19940.
PROG
(C) See Links section.
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Ilya Gutkovskiy, Sep 03 2019
EXTENSIONS
a(7) from Rémy Sigrist, Sep 04 2019
a(8)-a(9) from Giovanni Resta, Sep 04 2019
STATUS
approved