A368325 - OEIS

%I #93 Feb 02 2024 23:57:21

%S 1,2,4,6,8,16,30,32,64,128,210,256,512,1024,2048,2310,4096,8192,16384,

%T 30030,32768,65536,131072,262144,510510,524288,1048576,2097152,

%U 4194304,8388608,9699690,16777216,33554432,67108864,134217728,223092870,268435456,536870912,1073741824

%N Union of primorials and powers of 2.

%C Numbers that (1) are either prime powers or squarefree and (2) have a primorial kernel.

%H Michael De Vlieger, <a href="/A368325/b368325.txt">Table of n, a(n) for n = 1..3671</a>

%F Union of A000079 and A002110.

%F Intersection of A055932 and A303554.

%F Intersection of A025487 and A303554.

%F {a(n)} = A055932 \ A126706 = A025487 \ A126706.

%F A055932 = union of this sequence and A363814.

%F A025487 = union of this sequence and A364710.

%t Union@ Flatten@ {#, 2^Range[Log2[Last[#] ] ] } &@

%t   FoldList[Times, 1, Prime@ Range[nn]]

%Y Cf. A000079, A000961, A002110, A005117, A025487, A055932, A126706, A303554, A363814, A364710.

%K nonn,easy

%O 1,2

%A _Michael De Vlieger_, Jan 30 2024