

A106330


Numbers k such that k^2 = 24*(j^2) + 25.


1



5, 7, 11, 25, 59, 103, 245, 583, 1019, 2425, 5771, 10087, 24005, 57127, 99851, 237625, 565499, 988423, 2352245, 5597863, 9784379, 23284825, 55413131, 96855367, 230496005, 548533447, 958769291, 2281675225, 5429921339, 9490837543, 22586256245, 53750679943
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OFFSET

1,1


COMMENTS

The ratio k(n) /(2*j(n)) tends to sqrt(6) as n increases.


LINKS

Table of n, a(n) for n=1..32.
Index entries for linear recurrences with constant coefficients, signature (0,0,10,0,0,1).


FORMULA

Recurrence: k(1)=5, k(2)=7, k(3)=11, k(4)=25, k(5)=10*k(2)k(3), k(6)=10*k(3)k(2) then k(n)=10*k(n3)k(n6).
G.f.: (7x^511x^425x^3+11x^2+7x+5)/(x^610x^3+1).
a(3n+1) = 5*A001079(n), a(3n+2) = A077409(n), a(3n+3) = A077250(n).


PROG

(PARI) Vec(x*(7*x^5+11*x^4+25*x^311*x^27*x5)/(x^610*x^3+1) + O(x^100)) \\ Colin Barker, Apr 16 2014


CROSSREFS

Cf. A106331.
Sequence in context: A067289 A036491 A036490 * A057247 A157437 A213677
Adjacent sequences: A106327 A106328 A106329 * A106331 A106332 A106333


KEYWORD

nonn,easy


AUTHOR

Pierre CAMI, Apr 29 2005


EXTENSIONS

More terms, g.f. and formulas from Ralf Stephan, Nov 15 2010
More terms from Colin Barker, Apr 16 2014


STATUS

approved



