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A262018
The first of five consecutive positive integers the sum of the squares of which is equal to the sum of the squares of eleven consecutive positive integers.
3
28, 5308, 945148, 168231388, 29944242268, 5329906892668, 948693482652988, 168862110005339548, 30056506887467786908, 5349889363859260730428, 952250250260060942229628, 169495194656926988456143708, 30169192398682743884251350748, 5369946751770871484408284289788
OFFSET
1,1
COMMENTS
For the first of the corresponding eleven consecutive positive integers, see A262019.
FORMULA
a(n) = 179*a(n-1)-179*a(n-2)+a(n-3) for n>3.
G.f.: -4*x*(7*x^2+74*x+7) / ((x-1)*(x^2-178*x+1)).
EXAMPLE
28 is in the sequence because 28^2 + ... + 32^2 = 4510 = 15^2 + ... + 25^2.
MATHEMATICA
LinearRecurrence[{179, -179, 1}, {28, 5308, 945148}, 30] (* Harvey P. Dale, May 16 2019 *)
PROG
(PARI) Vec(-4*x*(7*x^2+74*x+7)/((x-1)*(x^2-178*x+1)) + O(x^20))
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Colin Barker, Sep 08 2015
STATUS
approved