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A259658 Let f(x) be the absolute value of the difference between x and its base-2 reversal. Let g(x) be the number of times f(x) must be applied to x for the result to be 0. a(n) is the smallest value of x for which g(x) is n. 1
0, 1, 2, 11, 38, 271, 544, 2093, 2624, 8607, 17984, 35343, 35904, 70671, 71744, 141327, 143424, 282639, 286784, 565263, 573504, 1130511, 1146944, 2261007, 2293824, 4521999, 4587584, 9043983, 9175104, 18087951, 18350144, 36175887, 36700224, 72351759, 73400384 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

f(x) = abs(A055945(x)).

LINKS

Alois P. Heinz, Table of n, a(n) for n = 0..1000

Index entries for linear recurrences with constant coefficients, signature (0,3,0,-2).

FORMULA

G.f.: -x*(18144*x^12 +12800*x^11 -13708*x^10 -11200*x^9 -2870*x^8 -1068*x^7 -1302*x^6 -434*x^5 -240*x^4 -32*x^3 -8*x^2 -2*x-1)/ ((x-1) *(x+1) *(2*x^2-1)). - Alois P. Heinz, Jul 02 2015

MATHEMATICA

CoefficientList[Series[x (18144 x^12 + 12800 x^11 - 13708 x^10 -11200 x^9 - 2870 x^8 - 1068 x^7 - 1302 x^6 - 434 x^5 - 240 x^4 - 32 x^3 - 8 x^2 - 2 x - 1)/((1 - x) (x + 1) (2 x^2 - 1)), {x, 0, 50}], x] (* Vincenzo Librandi, Jul 10 2015 *)

PROG

(MAGMA) I:=[0, 1, 2, 11, 38, 271, 544, 2093, 2624, 8607, 17984, 35343, 35904, 70671]; [n le 14 select I[n] else 3*Self(n-2)-2*Self(n-4): n in [1..50]]; // Vincenzo Librandi, Jul 10 2015

CROSSREFS

Cf. A030101, A055945.

Sequence in context: A166989 A143550 A259213 * A000175 A276659 A187259

Adjacent sequences:  A259655 A259656 A259657 * A259659 A259660 A259661

KEYWORD

nonn,base,easy

AUTHOR

Dylan Hamilton, Jul 02 2015

EXTENSIONS

a(0), a(19)-a(34) from Alois P. Heinz, Jul 02 2015

STATUS

approved

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Last modified June 16 14:12 EDT 2021. Contains 345057 sequences. (Running on oeis4.)