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a(n) = n + a(floor(sqrt(n))) for n > 1; a(1) = 1.
2

%I #5 May 17 2017 22:45:25

%S 1,3,4,7,8,9,10,11,13,14,15,16,17,18,19,23,24,25,26,27,28,29,30,31,33,

%T 34,35,36,37,38,39,40,41,42,43,45,46,47,48,49,50,51,52,53,54,55,56,57,

%U 59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,75,76,77,78,79,80,81,82

%N a(n) = n + a(floor(sqrt(n))) for n > 1; a(1) = 1.

%H Robert Israel, <a href="/A097044/b097044.txt">Table of n, a(n) for n = 1..10000</a>

%F a(1)=1; a(n) = n + a(floor(sqrt(n))) for n > 1.

%p f:= proc(n) option remember; n + procname(floor(sqrt(n))) end proc:

%p f(1):= 1:

%p map(f, [$1..100]); # _Robert Israel_, May 17 2017

%Y Cf. A097043 ( n - a(floor(sqrt(n))) ).

%K nonn

%O 1,2

%A _Rick L. Shepherd_, Jul 20 2004