%I #13 Aug 14 2023 15:00:02

%S 1,1,1,1,1,1,141,141,211,211,82321,82321,526093,526093,526093,526093,

%T 127890361,127890361

%N a(n) is the smallest number k such that the number of distinct prime divisors of the n numbers from k through k+n-1 are in nondescending order.

%C Smallest initial number k of n consecutive numbers satisfying omega(k) <= omega(k+1) <= ... <= omega(k+n-1).

%e a(9) = 211 = a(10) as omega(211) = 1 < omega(212) = omega(213) = omega(214) = omega(215) = omega(216) = omega(217) = omega(218) = omega(219) = 2 < omega(220) = 3.

%t k = 1; Do[While[t = Table[PrimeNu[i], {i, k, k + n - 1}]; t != Sort[t], k++]; Print[k], {n, 1, 16}]

%o (PARI) a(n) = my(k=1, list=List(vector(n, i, omega(i)))); while (vecsort(list) != list, listpop(list, 1); k++; listput(list, omega(k+n-1))); k; \\ _Michel Marcus_, Aug 14 2023

%Y Cf. A001221, A075046, A286287, A364804.

%K nonn,more

%O 1,7

%A _Ilya Gutkovskiy_, Aug 08 2023

%E a(17)-a(18) from _Michel Marcus_, Aug 14 2023