A323242 - OEIS

A323242

Lexicographically earliest sequence such that a(i) = a(j) => f(i) = f(j) for all i, j, where f(n<=2) = -n, f(n) = 0 if n is an even number > 2, and f(n) = A300226(n) for odd numbers >= 3.

1, 2, 3, 4, 3, 4, 3, 4, 5, 4, 3, 4, 3, 4, 6, 4, 3, 4, 3, 4, 6, 4, 3, 4, 7, 4, 8, 4, 3, 4, 3, 4, 6, 4, 9, 4, 3, 4, 6, 4, 3, 4, 3, 4, 10, 4, 3, 4, 11, 4, 6, 4, 3, 4, 9, 4, 6, 4, 3, 4, 3, 4, 10, 4, 9, 4, 3, 4, 6, 4, 3, 4, 3, 4, 12, 4, 13, 4, 3, 4, 14, 4, 3, 4, 9, 4, 6, 4, 3, 4, 13, 4, 6, 4, 9, 4, 3, 4, 10, 4, 3, 4, 3, 4, 15

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..100000

PROG

(PARI)

up_to = 10000;

rgs_transform(invec) = { my(om = Map(), outvec = vector(length(invec)), u=1); for(i=1, length(invec), if(mapisdefined(om, invec[i]), my(pp = mapget(om, invec[i])); outvec[i] = outvec[pp] , mapput(om, invec[i], i); outvec[i] = u; u++ )); outvec; };

A052126(n) = if(1==n, n, n/vecmax(factor(n)[, 1]));

A319988(n) = ((n>1)&&(factor(n)[omega(n), 2]>1));

A323242aux(n) = if(n<=2, -n, if(!(n%2), 0, [A052126(n), A319988(n)]));

v323242 = rgs_transform(vector(up_to, n, A323242aux(n)));

A323242(n) = v323242[n];

CROSSREFS

Cf. A052126, A300226, A319701, A319988, A323241.

Sequence in context: A285884 A123709 A165482 * A099034 A165576 A354705

Adjacent sequences: A323239 A323240 A323241 * A323243 A323244 A323245

KEYWORD

nonn

AUTHOR

Antti Karttunen, Jan 07 2019

STATUS

approved