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A074047 a(n)=a(n-1)*a(n-2)*a(n-3)*(1/a(n-1)+1/a(n-2)+1/a(n-3)) starting with a(1)=a(2)=a(3)=1. 2
1, 1, 1, 3, 7, 31, 331, 12795, 4642051, 60935796571, 283646808320375611, 17285560913056915909539455163, 4902995236325455290013100337511909917402705547 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,4
COMMENTS
Using the simplified formula which extends the original one to terms that may be zero, one could prefix the values (1, 1, 0), cf. A121810. See also A203761 and references therein. - M. F. Hasler, Jan 01 2013
LINKS
FORMULA
a(n) tends towards a(n-1)^phi and 1.22376...^(phi^n) where phi=(1+sqrt(5))/2=1.6180339887...
a(n)=a(n-1)*a(n-2)+a(n-3)*a(n-1)+a(n-2)*a(n-3). - M. F. Hasler, Jan 01 2013
EXAMPLE
a(7)=31*7*3*(1/31+1/7+1/3)=331.
MATHEMATICA
RecurrenceTable[{a[n]==a[n-1]*a[n-2]+a[n-3]*a[n-1]+a[n-2]*a[n-3], a[1]==1, a[2]==1, a[3]==1}, a[n], {n, 1, 15}] (* Vaclav Kotesovec, Jan 20 2014 *)
CROSSREFS
Cf. A074046.
Sequence in context: A063896 A277028 A156895 * A121810 A081475 A123212
KEYWORD
nonn
AUTHOR
Henry Bottomley, Aug 14 2002
STATUS
approved

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Last modified April 17 09:46 EDT 2024. Contains 371763 sequences. (Running on oeis4.)