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A361460
a(n) = 1 if A135504(n+1) = 2 * A135504(n), otherwise 0.
4
0, 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 1, 0, 0, 1, 0, 0, 1, 1, 0, 1, 0, 1, 0, 0, 1, 1, 0, 1, 0, 1, 0, 1, 0, 1, 1, 0, 0, 1, 1, 1, 0, 0, 0, 1, 1, 1, 1, 0, 0, 1, 0, 1, 1, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 1, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 0, 0, 1, 0, 1, 1, 0, 1, 1, 1, 0, 1, 0, 1, 1, 0, 0, 1, 0, 1, 1, 1, 0, 1, 0, 0, 1, 0, 1, 1, 1
OFFSET
1
FORMULA
a(n) = 1 if A135504(n) is a multiple of n+1, otherwise 0.
a(n) = [A135506(n) = 1], where [ ] is the Iverson bracket.
a(n) = 1 if A135506(n) is not prime, otherwise 0. [Conjectured]
PROG
(PARI)
up_to = 65537;
A135506list(up_to_n) = { my(v=vector(up_to), x1=1, x2); for(n=2, 1+up_to_n, x2 = x1+lcm(x1, n); v[n-1] = (x2/x1)-1; x1=x2); (v); };
v135506 = A135506list(up_to);
A135506(n) = v135506[n];
A361460(n) = (1==A135506(n));
(PARI)
A361460list(up_to_n) = { my(v=vector(up_to), x1=1, x2); for(n=2, 1+up_to_n, x2 = x1+lcm(x1, n); v[n-1] = !(x1%n); x1=x2); (v); };
v361460 = A361460list(up_to);
A361460(n) = v361460[n];
CROSSREFS
Characteristic function of A361461.
Sequence in context: A286691 A359172 A288462 * A130198 A285411 A372544
KEYWORD
nonn
AUTHOR
Antti Karttunen, Mar 13 2023
STATUS
approved