OFFSET
0,3
FORMULA
a(n) ~ (BesselI(0,1) + BesselI(1,1)) * 2^(n-1) * n!. - Vaclav Kotesovec, Jul 09 2015
MATHEMATICA
RecurrenceTable[{a[0]==0, a[1]==1, (n)*a[n+1]== (2n^2 +2*n+1)*a[n] + (n+1)*a[n-1]}, a, {n, 30}]
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
G. C. Greubel, Jul 07 2015
STATUS
approved