The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A010035 a(n) = 2*3^(2*n)-3^n. 2
 1, 15, 153, 1431, 13041, 117855, 1062153, 9563751, 86086881, 774821295, 6973509753, 62761942071, 564858541521, 5083730062335, 45753580126953, 411782249840391, 3706040334656961, 33354363270192975, 300189270206577753, 2701703434183722711, 24315330914627073201 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS Index entries for linear recurrences with constant coefficients, signature (12,-27). FORMULA a(n) = 12*a(n-1)-27*a(n-2). G.f.: (3*x+1) / ((3*x-1)*(9*x-1)). - Colin Barker, Oct 01 2014 MAPLE f := n->2*3^(2*n)-3^n; PROG (PARI) a(n) = 2*3^(2*n)-3^n \\ Michel Marcus, Jun 08 2013 CROSSREFS Sequence in context: A021124 A004322 A125403 * A334356 A017389 A278803 Adjacent sequences:  A010032 A010033 A010034 * A010036 A010037 A010038 KEYWORD nonn,easy AUTHOR Steve King (ITTTUCSON(AT)aol.com) EXTENSIONS Revised by N. J. A. Sloane, Jun 10 2013, replacing incorrect definition with formula from Michel Marcus which matches the terms. More terms, and corrections to name, Maple and prog to agree with the offset, from Colin Barker, Oct 01 2014 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified May 14 18:21 EDT 2021. Contains 343900 sequences. (Running on oeis4.)