



1, 2, 6, 12, 60, 180, 360, 420, 840, 1260, 2520, 5040, 13860, 27720, 55440, 83160, 166320, 277200, 360360, 720720, 1081080, 2162160, 2827440, 4324320, 6126120, 12252240, 24504480, 36756720, 73513440, 147026880, 183783600, 232792560, 367567200, 465585120, 698377680
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OFFSET

1,2


COMMENTS

Observation: a(n) ending at 0, if 5 <= n <= 24 and possibly more.
From David A. Corneth, Apr 14 2021: (Start)
Conjecture: for each term k > 1 in the sequence there exists prime p such that k/p is in the sequence.
From the first 35 terms only a(23) = 2827440 is not in A025487.
In the list of conjectured terms, if actual terms <= 10^16 are 97smooth and have the following property: a(n+1) = a(n) + k*gcd(a(n), a(n1), ..., a(n20)) setting a(n) = 1 for n < 1 then those terms are actual terms.
The conjectured terms are 41smooth and satisfy a(n+1) = a(n) + k*gcd(a(n), a(n1), ..., a(n13)). (End)


LINKS

Table of n, a(n) for n=1..35.
David A. Corneth, Conjectured terms <= 10^16 (a(1)..a(35) are certain)


CROSSREFS

Cf. A007862, A088726, A093687, A097212, A129308, A181826, A195155.
Sequence in context: A139315 A014767 A002319 * A101657 A104371 A104350
Adjacent sequences: A195304 A195305 A195306 * A195308 A195309 A195310


KEYWORD

nonn


AUTHOR

Omar E. Pol, Oct 16 2011


EXTENSIONS

More terms a(6)a(24) from Alois P. Heinz, Oct 16 2011
a(25)a(35) from David A. Corneth, Apr 14 2021


STATUS

approved



