OFFSET
1,1
LINKS
David A. Corneth, Table of n, a(n) for n = 1..10000 (first 600 terms from Harvey P. Dale)
EXAMPLE
203980 is a member since 2^2 | 203980, 37^2 | 203981, 13^2 | 203983, 2^2 | 203984, 3^2 | 203985, 7^2 | 203987, and 2^2 | 203988.
MATHEMATICA
Flatten[Position[Partition[Table[If[Divisible[n, FactorInteger[n][[1, 1]]^2], 1, 0], {n, 420000}], 10, 1], _?(Total[#]>6&)]] (* Harvey P. Dale, Jan 02 2021 *)
PROG
(PARI) upto(n) = {my(l, c, res); l = List([0, 0, 0, 1, 0, 0, 0, 1, 1, 0]); c = 3; res = List(); for(i = 11, n, f = factor(i)[, 2]; c -= l[1]; listpop(l, 1); if(f[1] >= 2, c++; listput(l, 1) , listput(l, 0) ); if(c >= 7, listput(res, i-9); ) ); res } \\ David A. Corneth, Jan 02 2021
CROSSREFS
KEYWORD
nonn
AUTHOR
Sean A. Irvine (on behalf of Donald S. McDonald), Nov 07 2019
STATUS
approved