A365413 - OEIS

A365413

a(1) = 2, a(n) = k - 1, where k is the least number greater than a(n-1) such that rad(k) | a(n-1), where rad(n) = A007947(n).

2, 3, 8, 15, 24, 26, 31, 960, 971, 942840, 944783, 946728, 948675, 950624, 952575, 954528, 956483, 958440, 959999, 2229048, 2232035, 2235024, 2238015, 2241008, 2244003, 2247000, 2249999, 2253000, 2256003, 2259008, 2262015, 2265024, 2268035, 2271048, 2274063, 2277080, 2280099

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OFFSET

1,1

LINKS

Table of n, a(n) for n=1..37.

FORMULA

a(n) = A289280(a(n-1)) - 1 for n > 1.

EXAMPLE

a(2) = 3 since 4 is the smallest k > a(1) such that rad(k) | a(1), and 4 - 1 = 3.

a(3) = 8 since 9 is the least k > a(2) such that rad(k) | a(2), and 9 - 1 = 8.

a(4) = 15 since 16 is the least k > a(3) such that rad(k) | a(3), and 16 - 1 = 15, etc.

MATHEMATICA