OFFSET
1,2
COMMENTS
This sequence is a primitive subsequence of A000379; it lists minimal terms in that sequence having their prime exponents.
LINKS
David A. Corneth, Table of n, a(n) for n = 1..10000
EXAMPLE
360 is a term as 360 = 2^3 * 3^2 * 5 which has exponents in binary 11_2, 10_2 and 1_2 respectively. The sum of binary digits of those exponents is (1 + 1) + (1 + 0) + 1 = 4 which is even. Furthermore, 360 is a product of primorials; 360 = 30 * 6 * 2. Therefore, 360 is in the sequence.
PROG
(PARI) is(n) = {if(n==1, return(1)); my(f = factor(n)); f[#f~, 1] == prime(#f~) && vecsort(f[, 2], , 4) == f[, 2] && !(sum(i=1, #f~, hammingweight(f[i, 2]))%2)}
CROSSREFS
KEYWORD
nonn
AUTHOR
David A. Corneth, Mar 20 2019
STATUS
approved