A144930 - OEIS

%I #23 Dec 31 2023 11:35:24

%S 1,109,11989,1318681,145042921,15953402629,1754729246269,

%T 193004263686961,21228714276319441,2334965566131451549,

%U 256824983560183350949,28248413226054037152841,3107068629882383903461561,341749300873836175343618869,37589316027492096903894614029

%N Numbers k arising in A144929.

%C Numbers n such that there exists x in N : (x+1)^3 - x^3 = 7*n^2. - _Richard Choulet_, Oct 16 2008

%D E.-A. Majol, Note #2228, L'Intermédiaire des Mathématiciens, 9 (1902), pp. 183-185. - _N. J. A. Sloane_, Mar 03 2022

%H Colin Barker, <a href="/A144930/b144930.txt">Table of n, a(n) for n = 1..450</a>

%H <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (110,-1).

%F a(n+2) = 110*a(n+1)-a(n). - _Richard Choulet_, Oct 16 2008

%F G.f.: -x*(x-1) / (x^2-110*x+1). - _Colin Barker_, Oct 17 2014

%e a(1) = 1 because 2^3-1^3 = 7*1. - _Richard Choulet_, Oct 16 2008

%t LinearRecurrence[{110,-1},{1,109},20] (* _Harvey P. Dale_, Oct 05 2016 *)

%o (PARI) Vec(-x*(x-1)/(x^2-110*x+1) + O(x^20)) \\ _Colin Barker_, Jul 14 2016

%Y Cf. A144729, A144727.

%K easy,nonn

%O 1,2

%A _Richard Choulet_, Sep 25 2008

%E More terms from _Colin Barker_, Oct 17 2014