

A152832


a(0) = 2; a(n) = n  a(n1) for n > 0.


13



2, 3, 1, 4, 0, 5, 1, 6, 2, 7, 3, 8, 4, 9, 5, 10, 6, 11, 7, 12, 8, 13, 9, 14, 10, 15, 11, 16, 12, 17, 13, 18, 14, 19, 15, 20, 16, 21, 17, 22, 18, 23, 19, 24, 20, 25, 21, 26, 22, 27, 23, 28, 24, 29, 25, 30, 26, 31, 27, 32, 28, 33, 29, 34, 30, 35, 31, 36, 32, 37, 33, 38, 34, 39, 35
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OFFSET

0,1


LINKS

Table of n, a(n) for n=0..74.
Index entries for linear recurrences with constant coefficients, signature (1,1,1).


FORMULA

From R. J. Mathar, Jan 03 2009, Aug 14 2009: (Start)
a(n) = (n+1)/2(9*(1)^n+1)/4.
G.f.: (2*x1)*(x2)/((1+x)*(x1)^2).
a(n) = a(n1)+a(n2)a(n3). (End)


MATHEMATICA

lst={}; a=2; Do[a=na; AppendTo[lst, a], {n, 0, 6!}]; lst
RecurrenceTable[{a[0]==2, a[n]==na[n1]}, a, {n, 80}] (* or *) With[ {nn=40}, Riffle[ Range[2, nn2], Range[3, nn+3]]] (* Harvey P. Dale, Jun 02 2019 *)


CROSSREFS

Cf. A084964
Sequence in context: A127412 A304791 A306646 * A211343 A039661 A293668
Adjacent sequences: A152829 A152830 A152831 * A152833 A152834 A152835


KEYWORD

sign


AUTHOR

Vladimir Joseph Stephan Orlovsky, Dec 14 2008


EXTENSIONS

Definition corrected by N. J. A. Sloane, Jan 11 2009
Formula adapted to offset by R. J. Mathar, Aug 14 2009


STATUS

approved



