A145278 Complement of A145198.

6, 12, 20, 24, 35, 56, 60, 72, 90, 110, 120, 140, 143, 182, 210, 240, 272, 280, 306, 342, 399, 420, 462, 504, 506, 575, 650, 702, 720, 756, 812, 840, 870, 930, 990, 992, 1056, 1120, 1122, 1224, 1332, 1406, 1430, 1482, 1560, 1640, 1722, 1806, 1892, 1980, 2002

Offset: 1

Author

Klaus Brockhaus, Oct 06 2008

Keywords

• nonn
• changed

Links

• Rémy Sigrist, Table of n, a(n) for n = 1..10000
• Rémy Sigrist, C program for A145278

Crossrefs

Cf. A145198.

Programs

C

/* See Links section. */

PARI

{m=2000; v=vector(m); z=2*m; u=vectorsmall(z); k=1; for(n=1, m, while(u[k], k++); v[n]=k; u[k]=1; j=n-1; p=k; while(j>0&&(p=p*v[j])<=z, u[p]=1; j--)); h=1; i=1; while(i<=m, if(h==v[i], i++, print1(h, ",")); h++)}

Python

from operator import mul
from itertools import count, accumulate, islice
from collections import deque
def A145278_gen(): # generator of terms
    aset, alist = set(), deque()
    for k in count(1):
        if k in aset:
            aset.remove(k)
            yield k
        else:
            aset |= set(k*d for d in accumulate(alist,mul))
            alist.appendleft(k)
A145278_list = list(islice(A145278_gen(),30)) # Chai Wah Wu, Sep 01 2025