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A104470
Tribonacci equivalent of mousetrap sequence (A002467).
1
1, 1, 1, 9, 44, 270, 1938, 15764, 143776, 1453302, 16128420, 194980478, 2550746400, 35904118874, 541097840528, 8693290587030, 148324680742912, 2678504175897990, 51039398650102776, 1023458322628129882
OFFSET
0,4
COMMENTS
The mousetrap sequence (A002467) can be defined in a Fibonacci-like way as: a(0) = a(1) = 1; for n>1 a(n) = n*(a(n-1)+a(n-2)). The current sequence is thus the tribonacci equivalent of that.
LINKS
FORMULA
a(0) = a(1) = a(2) = 1; for n>2 a(n) = n*(a(n-1)+a(n-2)+a(n-3)).
MATHEMATICA
RecurrenceTable[{a[0]==a[1]==a[2]==1, a[n]==n(a[n-1]+a[n-2]+a[n-3])}, a, {n, 20}] (* Harvey P. Dale, Dec 25 2018 *)
CROSSREFS
Cf. A002467.
Sequence in context: A099867 A228603 A297491 * A282722 A084023 A084016
KEYWORD
easy,nonn
AUTHOR
Jonathan Vos Post, Mar 09 2005
STATUS
approved