

A075299


Trajectory of 290 under the Reverse and Add! operation carried out in base 4, written in base 10.


5



290, 835, 1610, 4195, 17060, 23845, 46490, 89080, 138125, 255775, 506510, 1238395, 5127260, 8616205, 15984335, 31949470, 79793675, 315404860, 569392925, 1060061935, 2114961710, 5206421995, 20997654620, 35262166285
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OFFSET

0,1


COMMENTS

290 is conjectured (cf. A066450) to be the smallest number such that the Reverse and Add! algorithm in base 4 does not lead to a palindrome. Unlike 318 (cf. A075153) its trajectory does not exhibit any recognizable regularity, so that the method by which the base 4 trajectory of 318 as well as the base 2 trajectories of 22 (cf. A061561), 77 (cf. A075253), 442 (cf. A075268) etc. can be proved to be palindromefree (cf. Links), is not applicable here.


LINKS

Table of n, a(n) for n=0..23.
Klaus Brockhaus, On the 'Reverse and Add!' algorithm in base 2
David J. Seal, Results
Index entries for sequences related to Reverse and Add!


EXAMPLE

290 (decimal) = 10202 > 10202 + 20201 = 31003 = 835 (decimal).


MATHEMATICA

NestWhileList[# + IntegerReverse[#, 4] &, 290, # !=
IntegerReverse[#, 4] &, 1, 23] (* Robert Price, Oct 18 2019 *)


PROG

(PARI) {m=290; stop=26; c=0; while(c<stop, print1(k=m, ", "); rev=0; while(k>0, d=divrem(k, 4); k=d[1]; rev=4*rev+d[2]); c++; m=m+rev)}


CROSSREFS

Cf. A066450, A075153, A058042, A061561, A075253, A075268.
Sequence in context: A090839 A158255 A295483 * A031712 A251049 A108881
Adjacent sequences: A075296 A075297 A075298 * A075300 A075301 A075302


KEYWORD

base,nonn


AUTHOR

Klaus Brockhaus, Sep 12 2002


STATUS

approved



