|
| |
|
|
A081955
|
|
a(n) = 2^r*3^s where r = n(n+1)/2 and s = n(n-1)/2.
|
|
4
| |
|
|
1, 2, 24, 1728, 746496, 1934917632, 30091839012864, 2807929681968365568, 1572081206902992767287296, 5280985496827154199640037916672, 106440332834866049138191223105387495424, 12872079797383178927229037635891253693013557248
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,2
|
|
|
FORMULA
| a(n+1) = 2^(n+1)*3^n*a(n), a(1) = 2. - Ryan Propper (rpropper(AT)stanford.edu), Jun 15 2005
A171795(n) = a(-n). a(n+1) * a(n-1) = 6 * a(n)^2. - Michael Somos Dec 17 2009
|
|
|
MATHEMATICA
| Do[Print[2^(n*(n+1)/2)*3^(n*(n-1)/2)], {n, 10}] (Propper)
|
|
|
PROG
| (PARI) {a(n) = 3^(n*(n-1)/2) * 2^(n*(n+1)/2)} /* Michael Somos Dec 17 2009 */
|
|
|
CROSSREFS
| Sequence contains the product of a row in A081954.
Cf. A025192, A081954, A081956.
Sequence in context: A000479 A181231 A111427 * A163086 A053995 A184595
Adjacent sequences: A081952 A081953 A081954 * A081956 A081957 A081958
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Apr 02 2003
|
|
|
EXTENSIONS
| More terms from Ryan Propper (rpropper(AT)stanford.edu), Jun 15 2005
|
| |
|
|
