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A086650 n-th composite number raised to the n-th prime number. 3
16, 216, 32768, 4782969, 100000000000, 106993205379072, 30491346729331195904, 22168378200531005859375, 4951760157141521099596496896, 2528731089327963353099650821015994368 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
This sequence arises as a result of exponentiation using the terms of the sequence A002808 as the base and the terms of the sequence A000040 as the exponent. This sequence has the very special and rare property of double exponential growth, meaning that its rate of growth grows. This property is due to the unregular growth of the prime exponent in the generating function for this sequence.
LINKS
FORMULA
a(n) = A002808(n)^A000040(n).
EXAMPLE
a(3)=8^5=32768 because 8 is the 3rd composite number and 5 is the 3rd prime number.
MATHEMATICA
Select[ Rest[ Range[ 18]], !PrimeQ[ # ] &]^Prime[ Range[18 - PrimePi[18] - 1]] (* Robert G. Wilson v, Oct 21 2005 *)
Module[{c=Select[Range[20], CompositeQ]}, #[[1]]^#[[2]]&/@Thread[ {c, Prime[ Range[ Length[c]]]}]] (* Harvey P. Dale, Apr 05 2019 *)
CROSSREFS
Sequence in context: A181247 A138454 A235758 * A137701 A080514 A081969
KEYWORD
easy,nonn
AUTHOR
Christopher M. Tomaszewski (cmt1288(AT)comcast.net), Jul 26 2003
STATUS
approved

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Last modified March 5 05:51 EST 2024. Contains 370537 sequences. (Running on oeis4.)