A369060 LCM-transform of Sycamore's D(3) variant of Doudna sequence (A356867).

1, 2, 3, 5, 2, 1, 1, 2, 3, 7, 1, 1, 5, 1, 1, 1, 2, 1, 1, 1, 1, 5, 1, 1, 1, 2, 3, 11, 1, 1, 1, 1, 1, 1, 1, 1, 7, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 5, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 7, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 5, 1, 1, 1, 2, 3, 13, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1

Offset

1,2

Comments

See discussion at A368900.

Links

Antti Karttunen, Table of n, a(n) for n = 1..19683

Formula

a(n) = lcm {1..A356867(n)} / lcm {1..A356867(n-1)}.

a(n) = A014963(A356867(n)). [This holds because A356867 satisfies the property S explained in A368900]

Prog

(PARI)
up_to = 3^9; \\ Checked up to (3^12)
A356867list(up_to) = { my(v=vector(up_to), met=Map(), h=0, ak); for(i=1, #v, if(1==sumdigits(i, 3), v[i] = i; h = i, ak = v[i-h]; forprime(p=2, , if(3!=p && !mapisdefined(met, p*ak), v[i] = p*ak; break))); mapput(met, v[i], i)); (v); };
v356867 = A356867list(up_to);
A356867(n) = v356867[n];
LCMtransform(v) = { my(len = length(v), b = vector(len), g = vector(len)); b[1] = g[1] = 1; for(n=2, len, g[n] = lcm(g[n-1], v[n]); b[n] = g[n]/g[n-1]); (b); };
v369060 = LCMtransform(v356867);
A369060(n) = v369060[n];
A014963(n) = { ispower(n, , &n); if(isprime(n), n, 1); };

Crossrefs

Cf. A014963, A356867, A368900.

Sequence in context: A171035 A094122 A280185 * A369686 A082117 A269701

Adjacent sequences: A369057 A369058 A369059 * A369061 A369062 A369063

Keyword

nonn

Author

Antti Karttunen, Jan 13 2024

Status

approved