login

Revision History for A278475

(Bold, blue-underlined text is an addition; faded, red-underlined text is a deletion.)

Showing all changes.
a(n) = floor(phi^7*a(n-1)) for n>0, a(0) = 1, where phi is the golden ratio (A001622).
(history; published version)
#8 by N. J. A. Sloane at Sun Nov 27 21:46:17 EST 2016
STATUS

proposed

approved

#7 by G. C. Greubel at Thu Nov 24 16:05:24 EST 2016
STATUS

editing

proposed

#6 by G. C. Greubel at Thu Nov 24 16:05:17 EST 2016
PROG

(PARI) Vec( (1 - x - x^2)/((1 - x)*(1 - 29*x - x^2)) + O(x^50) ) \\ G. C. Greubel, Nov 24 2016

STATUS

proposed

editing

#5 by Ilya Gutkovskiy at Wed Nov 23 04:59:27 EST 2016
STATUS

editing

proposed

#4 by Ilya Gutkovskiy at Wed Nov 23 04:52:50 EST 2016
COMMENTS

In general, the ordinary generating function for the recurrence relation b(n) = floor(phi^k*b(n - 1)) with n>0 and b(0) = 1, is (1 - x)/(1 - (phi^k + (-phi)^(-k))*x + x^2) if k is even, and (1 - x - x^2)/((1 - x)*(1 - (phi^k + (-phi)^(-k))*x - x^2)) if k is odd.

#3 by Ilya Gutkovskiy at Wed Nov 23 04:26:24 EST 2016
FORMULA

a(n) = ((-29 - 13 *sqrt(5))^(-n)*(-7*(407 + 182*sqrt(5))*2^(n+3) + 13*(1885 + 843*sqrt(5))*(-29 - 13*sqrt(5))^n + 28*(25319 + 11323*sqrt(5))*(-843 - 377*sqrt(5))^n))/(377*(1885 + 843*sqrt(5))).

#2 by Ilya Gutkovskiy at Wed Nov 23 04:25:01 EST 2016
NAME

allocated a(n) = floor(phi^7*a(n-1)) for Ilya Gutkovskiyn>0, a(0) = 1, where phi is the golden ratio (A001622).

DATA

1, 29, 841, 24417, 708933, 20583473, 597629649, 17351843293, 503801085145, 14627583312497, 424703717147557, 12331035380591649, 358024729754305377, 10395048198255447581, 301814422479162285225, 8763013300093961719105, 254429200125204052139269, 7387209816931011473757905

OFFSET

0,2

COMMENTS

In general, the ordinary generating function for the recurrence relation b(n) = floor(phi^k*b(n - 1)) with n>0 and b(0)=1, is (1 - x)/(1 - (phi^k + (-phi)^(-k))*x + x^2) if k is even, and (1 - x - x^2)/((1 - x)*(1 - (phi^k + (-phi)^(-k))*x - x^2)) if k is odd.

LINKS

<a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (30,-28,-1).

FORMULA

G.f.: (1 - x - x^2)/((1 - x)*(1 - 29*x - x^2)).

a(n) = 30*a(n-1) - 28*a(n-2) - a(n-3).

a(n) = ((-29 - 13 sqrt(5))^(-n)*(-7*(407 + 182*sqrt(5))*2^(n+3) + 13*(1885 + 843*sqrt(5))*(-29 - 13*sqrt(5))^n + 28*(25319 + 11323*sqrt(5))*(-843 - 377*sqrt(5))^n))/(377*(1885 + 843*sqrt(5))).

MATHEMATICA

RecurrenceTable[{a[0] == 1, a[n] == Floor[GoldenRatio^7 a[n - 1]]}, a, {n, 17}]

LinearRecurrence[{30, -28, -1}, {1, 29, 841}, 18]

CROSSREFS

Cf. A001622.

Cf. similar sequences with recurrence relation b(n) = floor(phi^k*b(n-1)) for n>0, b(0) = 1: A000012 (k = 1), A001519 (k = 2), A024551 (k = 3), A049685 (k = 4), A214993 (k = 5), A007805 (k = 6), this sequence (k = 7).

KEYWORD

allocated

nonn,easy

AUTHOR

Ilya Gutkovskiy, Nov 23 2016

STATUS

approved

editing

#1 by Ilya Gutkovskiy at Wed Nov 23 04:25:01 EST 2016
NAME

allocated for Ilya Gutkovskiy

KEYWORD

allocated

STATUS

approved