A292427 Least number k > primorial(n) such that omega(k) = n-1.

7, 33, 220, 2340, 30090, 511290, 9708270, 223136760, 6470164470, 200575098570, 7420875422730, 304251077160030, 13082794956764610, 614890302617971380, 32589185235841244010, 1922761748060828845170, 117288389032450202376810, 7858321607905303633368270

Offset

2,1

Links

Table of n, a(n) for n=2..19.

Prog

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

Crossrefs

Cf. A001221, A002110, A292426.

Sequence in context: A054256 A085636 A064306 * A333565 A215125 A204706

Adjacent sequences: A292424 A292425 A292426 * A292428 A292429 A292430

Keyword

nonn

Author

Gionata Neri, Sep 30 2017

Extensions

a(12)-a(19) from Daniel Suteu, Sep 22 2023

Status

approved