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Numbers n for which there does not exist any x > n such that A155043(x) < A155043(n).
6

%I #16 Oct 24 2015 12:24:18

%S 1,2,3,4,6,8,9,10,12,14,18,20,22,24,25,26,28,30,32,34,38,40,42,44,46,

%T 48,49,50,52,54,56,60,72,84,96,104,108,120,128,132,136,140,142,144,

%U 150,152,156,160,162,168,170,180,182,184,186,188,190,192,194,198,200,204,208,210,216,220,225,228,240,248,252,260,264,276,280,288,296,300,308,312,320,328,340,352,360

%N Numbers n for which there does not exist any x > n such that A155043(x) < A155043(n).

%C Numbers n for which A263077(n) < n.

%C Numbers n for which A263078(n) is negative.

%C Numbers n at which point A155043(n) is the greatest lower bound for the rest of its terms from A155043(n) onward.

%H Antti Karttunen, <a href="/A263079/b263079.txt">Table of n, a(n) for n = 1..9165</a>

%e 1 is present because A049820(1) = 0, thus A155043(1) = 1, while all the larger numbers require at least the same number of steps to reach zero.

%t a[0] = 0; a[n_] := a[n] = 1 + a[n - DivisorSigma[0, n]]; Position[Table[k = 3 n; While[a@ k >= a@ n, k--]; k - n, {n, 200}], _Integer?Negative] // Flatten (* _Michael De Vlieger_, Oct 13 2015 *)

%o (PARI)

%o n=0; i=0; while(n < 124340, n++; if((A263077(n) < n), i++; write("b263079.txt",i," ",n)));

%o \\ Other code as in A263077.

%o (Scheme, with _Antti Karttunen_'s IntSeq-library)

%o (define A263079 (MATCHING-POS 1 1 (COMPOSE negative? A263078)))

%Y Cf. A155043, A261089, A262503, A263077, A263078.

%Y Complement: A263080.

%K nonn

%O 1,2

%A _Antti Karttunen_, Oct 09 2015