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A145335
Numbers n such that there exists x in N : (x+1)^3-x^3=43*n^2.
1
7, 235963, 7954312723, 268139881656367, 9038995402681818847, 304704534756264231676003, 10271589857594671847116242283, 346255293794811853210024295683927, 11672265943551517714115247160388936887, 393472084610866368348013128566686766776843
OFFSET
1,1
FORMULA
a(n+2) = 33710*a(n+1)-a(n).
a(n) = A145333(n)/1849. - Colin Barker, Oct 20 2014
G.f.: -7*x*(x-1) / (x^2-33710*x+1). - Colin Barker, Oct 20 2014
EXAMPLE
a(1)=7 because the first relation is : 27^3-26^3=43*7^2.
MATHEMATICA
LinearRecurrence[{33710, -1}, {7, 235963}, 15] (* Paolo Xausa, Jan 17 2024 *)
PROG
(PARI) Vec(-7*x*(x-1)/(x^2-33710*x+1) + O(x^20)) \\ Colin Barker, Oct 20 2014
CROSSREFS
Cf. A145333.
Sequence in context: A297059 A306256 A145322 * A003835 A138878 A050938
KEYWORD
easy,nonn
AUTHOR
Richard Choulet, Oct 08 2008
EXTENSIONS
Editing and more terms from Colin Barker, Oct 20 2014
STATUS
approved