login
A238243
A recursive sequence: a(n) = Fibonacci(n)*a(n-1) + 2.
3
1, 3, 8, 26, 132, 1058, 13756, 288878, 9821854, 540201972, 48077975510, 6923228473442, 1613112234311988, 608143312335619478, 370967420524727881582, 366144844057906419121436, 584733315960476551336933294, 1510950888441871408654635631698
OFFSET
1,2
FORMULA
a(n) ~ c * ((1+sqrt(5))/2)^(n^2/2+n/2) / 5^(n/2), where c = A062073 * (2*A101689-1) = 5.4087126382942177293... is product of Fibonacci factorial constant (see A062073) and -1+2*sum_{n>=1} 1/product(A000045(k), k=1..n).
MATHEMATICA
RecurrenceTable[{a[n]==Fibonacci[n]*a[n-1]+2, a[1]==1}, a, {n, 1, 20}]
KEYWORD
nonn
AUTHOR
Vaclav Kotesovec, Feb 20 2014
STATUS
approved