OFFSET
0,2
COMMENTS
Next term has 110 digits.
a(n) = first counting number with n distinct positive tetrahedral exponents in its prime factorization (cf. A000292).
Note: a(n) is not the first counting number with n distinct square exponents in its prime factorization, as previously stated. That sequence is A212170. - Matthew Vandermast, May 23 2012
LINKS
FORMULA
a(n) = Product_{k=1..n} prime(k)^((n-k+1)^2).
EXAMPLE
a(3) = 414720 = 2^10*3^4*5^1 has 3 positive tetrahedral exponents in its prime factorization (cf. A000292). It is the smallest number with this property.
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Matthew Vandermast, Nov 05 2009
EXTENSIONS
Offset corrected by Matthew Vandermast, Nov 07 2009
Edited by Matthew Vandermast, Nov 10 2009, May 23 2012
Name changed by Arkadiusz Wesolowski, Feb 21 2014
STATUS
approved