OFFSET
1,2
COMMENTS
FORMULA
For m >= 1, a(n) = P(m) = A002110(m)-->a(n+1) = prime(m+1), a(n+2) = 2*P(m), a(n+3) = 2*prime(m+1); (see last in Example).
EXAMPLE
a(1) = 1--> a(2) = 2 since 2 is the least primorial exceeding 1.
a(2) = 2--> a(3) = 3 since 2*3 = 6, the next primorial, and no k < 3 is such that rad(k*2) = 6.
a(3) = 3--> a(4) = 4 since rad(3*4) = rad(12) = 6.
a(4) = 4-->a(5) = 6 since rad(4*6) = rad(24) = 6.
a(58,59,60,61) = 2310,13,4620,26 = P(5), prime(6), 2*P(5), 2*prime(6).
CROSSREFS
KEYWORD
nonn
AUTHOR
David James Sycamore, Feb 28 2024
STATUS
approved