|
|
A075414
|
|
Squares of A002279: a(n) = (5*(10^n - 1)/9)^2.
|
|
9
|
|
|
0, 25, 3025, 308025, 30858025, 3086358025, 308641358025, 30864191358025, 3086419691358025, 308641974691358025, 30864197524691358025, 3086419753024691358025, 308641975308024691358025
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,2
|
|
COMMENTS
|
A transformation of the Wonderful Demlo numbers (A002477).
|
|
LINKS
|
|
|
FORMULA
|
G.f.: 25*x*(1 + 10*x) / ((1 - x)*(1 - 10*x)*(1 - 100*x)).
a(n) = 111*a(n-1) - 1110*a(n-2) + 1000*a(n-3) for n>2.
a(n) = 25*(10^n-1)^2/81.
(End)
|
|
EXAMPLE
|
a(2) = 55^2 = 3025.
|
|
PROG
|
(PARI) concat(0, Vec(25*x*(1 + 10*x) / ((1 - x)*(1 - 10*x)*(1 - 100*x)) + O(x^20))) \\ Colin Barker, Jul 17 2019
|
|
CROSSREFS
|
|
|
KEYWORD
|
easy,nonn
|
|
AUTHOR
|
Michael Taylor (michael.taylor(AT)vf.vodafone.co.uk), Sep 14 2002
|
|
STATUS
|
approved
|
|
|
|