A248012 a(n)=p1^(p2^(p3^(p4^...)))... where p1<p2<p3<... are the distinct prime factors of n.

2, 3, 2, 5, 8, 7, 2, 3, 32, 11, 8, 13, 128, 243, 2, 17, 8, 19, 32, 2187, 2048, 23, 8, 5, 8192, 3, 128, 29, 14134776518227074636666380005943348126619871175004951664972849610340958208, 31, 2, 177147, 131072, 78125, 8, 37, 524288, 1594323, 32, 41

Offset

2,1

Links

Reinhard Zumkeller, Table of n, a(n) for n = 2..65, 65 = 2*3*11-1

Example

To find a(14) we first find the distinct prime factors of 14 which are 2 and 7, which leads to a(14)=2^7=128.
To find a(8) we find 8's prime factors, 8=2*2*2, the distinct prime factor is 2 therefore a(8)=2.
30 has 3 distinct prime factors {2,3,5}, so a(30)=2^(3^5)=14134776518227074636666380005943348126619871175004951664972849610340958208.

Prog

(Haskell)
a248012 = foldr1 (^) . a027748_row  -- Reinhard Zumkeller, Sep 29 2014

Crossrefs

Cf. A027748.

Sequence in context: A323382 A372597 A064939 * A151549 A086989 A110642

Adjacent sequences: A248009 A248010 A248011 * A248013 A248014 A248015

Keyword

nonn

Author

Talha Ali, Sep 29 2014

Status

approved