

A073216


The terms of A055235 (sums of two powers of 3) divided by 2.


2



1, 2, 3, 5, 6, 9, 14, 15, 18, 27, 41, 42, 45, 54, 81, 122, 123, 126, 135, 162, 243, 365, 366, 369, 378, 405, 486, 729, 1094, 1095, 1098, 1107, 1134, 1215, 1458, 2187
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OFFSET

1,2


COMMENTS

n such that 3 is the largest power of 3 dividing binomial(3n,n).  Benoit Cloitre, Jan 01 2004
Equals A023745 + 1.
This sequence is A007051 together with its (successive) multiples by (powers of) 3.  R. K. Guy, Oct 08 2011


LINKS

Table of n, a(n) for n=1..36.
C. Armana, Coefficients of Drinfeld modular forms and Hecke operators, Journal of Number Theory 131 (2011), 14351460.


FORMULA

(3^n + 3^m) / 2, n = 0, 1, 2, 3 ..., m = 0, 1, 2, 3, ... n.


EXAMPLE

a(4) = 5 = (3^2+3^0) / 2.


CROSSREFS

Cf. A055235, A007051, A023745.
Sequence in context: A087900 A101216 A175095 * A181902 A295631 A278707
Adjacent sequences: A073213 A073214 A073215 * A073217 A073218 A073219


KEYWORD

easy,nonn


AUTHOR

Jeremy Gardiner, Jul 21 2002


EXTENSIONS

Edited by Jeremy Gardiner, Oct 08 2011


STATUS

approved



