

A309907


a(n) is the square of the number consisting of one 1 and n 3's: (133...3)^2.


3



1, 169, 17689, 1776889, 177768889, 17777688889, 1777776888889, 177777768888889, 17777777688888889, 1777777776888888889, 177777777768888888889, 17777777777688888888889, 1777777777776888888888889, 177777777777768888888888889, 17777777777777688888888888889
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OFFSET

0,2


COMMENTS

All terms are zeroless (elements of A052382).


LINKS

Seiichi Manyama, Table of n, a(n) for n = 0..500
Index entries for linear recurrences with constant coefficients, signature (111,1110,1000).


FORMULA

G.f.: (40*x^2+58*x+1)/((x1)*(100*x1)*(10*x1)).
a(n) = A097166(n)^2 = ((4*10^n1)/3)^2.  Seiichi Manyama, Aug 23 2019


MAPLE

a:= n> parse(cat(1, 3$n))^2:
seq(a(n), n=0..18);


PROG

(PARI) {a(n) = ((4*10^n1)/3)^2} \\ Seiichi Manyama, Aug 23 2019


CROSSREFS

Cf. A052382, A097166, A102807.
Sequence in context: A264276 A231769 A069297 * A264222 A051477 A227692
Adjacent sequences: A309904 A309905 A309906 * A309908 A309909 A309910


KEYWORD

nonn,base,easy


AUTHOR

Alois P. Heinz, Aug 21 2019


STATUS

approved



