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Characteristic function for A000960.
7

%I #27 Apr 25 2024 09:56:01

%S 1,0,1,0,0,0,1,0,0,0,0,0,1,0,0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,

%T 0,0,0,0,1,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,

%U 0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1

%N Characteristic function for A000960.

%H Antti Karttunen, <a href="/A278169/b278169.txt">Table of n, a(n) for n = 1..9889</a>

%H <a href="/index/Ch#char_fns">Index entries for characteristic functions</a>

%F a(1) = 1; for n > 1, a(n) = A100617(n) - A100617(n-1).

%t b[n_] := (For[m = n; i = 1, i <= n-1, i++, d = n-i; m = d*Ceiling[m/d+1]]; m); A000960 = Array[b, 12]; Boole[MemberQ[A000960, #]]& /@ Range[A000960 // Last] (* _Jean-François Alcover_, Nov 24 2016 *)

%o (Scheme) (define (A278169 n) (if (= 1 n) n (- (A100617 n) (A100617 (- n 1)))))

%Y Characteristic function of A000960.

%Y Cf. A100617 (partial sums).

%K nonn

%O 1

%A _Antti Karttunen_, Nov 23 2016