A292427 - OEIS

%I #45 Sep 22 2023 04:42:42

%S 7,33,220,2340,30090,511290,9708270,223136760,6470164470,200575098570,

%T 7420875422730,304251077160030,13082794956764610,614890302617971380,

%U 32589185235841244010,1922761748060828845170,117288389032450202376810,7858321607905303633368270

%N Least number k > primorial(n) such that omega(k) = n-1.

%o (PARI) a(n) = b=prod(i=1, n, prime(i)); k={my(k=1); while(omega(b+k)<(n-1), k++); k; }; b+k

%o (PARI) a(n) = my(A=vecprod(primes(n)), B=2*A); (f(m, p, j) = my(r=oo); forprime(q=p, sqrtnint(B\m, j), my(v=m*q); while(v <= B, if(j==1, if(v>=A && v < r, r = v; B = v-1), if(v*(q+1) <= B, r = min(r, f(v, q+1, j-1)))); v *= q)); r); f(1, 2, n-1); \\ _Daniel Suteu_, Sep 22 2023

%Y Cf. A001221, A002110, A292426.

%K nonn

%O 2,1

%A _Gionata Neri_, Sep 30 2017

%E a(12)-a(19) from _Daniel Suteu_, Sep 22 2023