A075414 - OEIS

A075414

Squares of A002279: a(n) = (5*(10^n - 1)/9)^2.

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

Colin Barker, Table of n, a(n) for n = 0..100

G. Villemin, Variations sur les carrés

Index entries for linear recurrences with constant coefficients, signature (111,-1110,1000).

FORMULA

a(n) = A002279(n)^2 = (5 * A002275(n) )^2 = 25 * (A002275(n) )^2.

From Colin Barker, Jul 17 2019: (Start)

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

Cf. A075411, A075412, A075413, A075414, A075415, A075416, A075417, A002283.

Sequence in context: A014797 A077519 A078215 * A226277 A013737 A018861

Adjacent sequences: A075411 A075412 A075413 * A075415 A075416 A075417

KEYWORD

easy,nonn

AUTHOR

Michael Taylor (michael.taylor(AT)vf.vodafone.co.uk), Sep 14 2002

STATUS

approved