A332900 Lexicographically earliest infinite sequence such that a(i) = a(j) => f(i) = f(j), where f(n) = 0 if n > 1 and n is a square or twice square, with f(n) = n for all other numbers.

1, 2, 3, 2, 4, 5, 6, 2, 2, 7, 8, 9, 10, 11, 12, 2, 13, 2, 14, 15, 16, 17, 18, 19, 2, 20, 21, 22, 23, 24, 25, 2, 26, 27, 28, 2, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 2, 2, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 2, 54, 55, 56, 57, 58, 59, 60, 2, 61, 62, 63, 64, 65, 66, 67, 68, 2, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 2, 85, 2

Offset

1,2

Comments

For all i, j:

A324400(i) = A324400(j) => a(i) = a(j),

a(i) = a(j) => A292383(i) = A292383(j) => A292583(i) = A292583(j),

a(i) = a(j) => A332896(i) = A332896(j) => A332901(i) = A332901(j).

Links

Antti Karttunen, Table of n, a(n) for n = 1..65537

Prog

(PARI)
up_to = 65537;
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; };
A332900aux(n) = if((n>1)&&(issquare(n)||issquare(2*n)), 0, n);
v332900 = rgs_transform(vector(up_to, n, A332900aux(n)));
A332900(n) = v332900[n];

Crossrefs

Cf. A292383, A292583, A324400, A332896, A332901.

Sequence in context: A120641 A008666 A240854 * A336150 A336151 A286621

Adjacent sequences: A332897 A332898 A332899 * A332901 A332902 A332903

Keyword

nonn

Author

Antti Karttunen, Mar 05 2020

Status

approved