cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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.

Original entry on oeis.org

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

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Author

Antti Karttunen, Mar 05 2020

Keywords

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).

Crossrefs

Programs

  • 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];