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A013778
a(n) = 3^(4*n + 1).
2
3, 243, 19683, 1594323, 129140163, 10460353203, 847288609443, 68630377364883, 5559060566555523, 450283905890997363, 36472996377170786403, 2954312706550833698643, 239299329230617529590083, 19383245667680019896796723
OFFSET
0,1
COMMENTS
Equivalently, powers of 3 with final digit 3. - Muniru A Asiru, Feb 06 2019
FORMULA
From Philippe Deléham, Nov 25 2008: (Start)
a(n) = 81*a(n-1); a(0)=3.
G.f.: 3/(1-81*x). (End)
MAPLE
seq(coeff(series(3/(1-81*x), x, n+1), x, n), n = 0 .. 15); # Muniru A Asiru, Feb 06 2019
MATHEMATICA
3^(1 + 4Range[0, 15]) (* Harvey P. Dale, Jan 31 2011 *)
NestList[81#&, 3, 20] (* Harvey P. Dale, Feb 26 2023 *)
PROG
(Magma) [3^(4*n+1): n in [0..20]]; // Vincenzo Librandi, Jun 27 2011
(Maxima) makelist(3^(4*n+1), n, 0, 20); /* Martin Ettl, Oct 21 2012 */
(GAP) List([0..15], n->3^(4*n+1)); # Muniru A Asiru, Feb 06 2019
CROSSREFS
Sequence in context: A324444 A236249 A338453 * A146313 A092799 A229690
KEYWORD
nonn,easy
STATUS
approved