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A239674
Where records occur in A239656 (the first differences of sphenic numbers).
4
1, 2, 19, 498, 2114, 8351, 8381, 59704, 233890, 291963, 1119181, 1507131, 1839746, 9768399, 40844982, 94852115, 138032741, 443653568, 453853664, 2491818901
OFFSET
1,2
FORMULA
A239656(a(n)) = A239673(n).
PROG
(Haskell)
a239674 n = a239674_list !! (n-1)
-- See A239673 for definition of A239674_list.
(PARI) list(lim)=my(v=List(), t); forprime(p=2, (lim)^(1/3), forprime(q=p+1, sqrt(lim\p), t=p*q; forprime(r=q+1, lim\t, listput(v, t*r)))); vecsort(Vec(v)) ; \\ A007304
chk(lim) = my(v=list(lim), dv = vector(#v-1, k, v[k+1] - v[k]), r=0); for (i=1, #dv, if (dv[i] > r, r=dv[i]; print1(i, ", ")); ); \\ Michel Marcus, Sep 20 2023
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Reinhard Zumkeller, Mar 23 2014
EXTENSIONS
a(12)-a(14) from Michel Marcus, Sep 20 2023
a(15)-a(20) from Amiram Eldar, May 19 2024
STATUS
approved