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.

A322023 Lexicographically earliest such sequence a that a(i) = a(j) => A081373(i) = A081373(j) and A303756(i) = A303756(j), for all i, j. Here A081373 and A303756 are the ordinal transforms of Euler phi and Carmichael lambda.

Original entry on oeis.org

1, 2, 1, 2, 1, 3, 1, 4, 2, 5, 1, 6, 1, 3, 7, 4, 1, 8, 1, 9, 10, 2, 1, 11, 1, 5, 2, 11, 1, 12, 1, 13, 14, 5, 7, 15, 1, 3, 4, 16, 1, 17, 1, 18, 9, 2, 1, 19, 2, 20, 7, 11, 1, 8, 14, 21, 10, 2, 1, 22, 1, 2, 23, 4, 24, 25, 1, 9, 7, 17, 1, 26, 1, 20, 18, 12, 14, 27, 1, 28, 1, 20, 1, 29, 30, 3, 7, 12, 1, 31, 32, 4, 18, 2, 3, 33, 1, 8, 6, 34, 1, 35, 1, 36, 37
Offset: 1

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Author

Antti Karttunen, Nov 29 2018

Keywords

Comments

Restricted growth sequence transform of the ordered pair [A081373(n), A303756(n)].

Crossrefs

Cf. A000010, A002322, A081373, A303756, A319339, A322024, A322025 (ordinal transform).

Programs

  • PARI
    up_to = 65537;
    ordinal_transform(invec) = { my(om = Map(), outvec = vector(length(invec)), pt); for(i=1, length(invec), if(mapisdefined(om,invec[i]), pt = mapget(om, invec[i]), pt = 0); outvec[i] = (1+pt); mapput(om,invec[i],(1+pt))); outvec; };
    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; };
    A002322(n) = lcm(znstar(n)[2]); \\ From A002322
    v081373 = ordinal_transform(vector(up_to,n,eulerphi(n)));
    A081373(n) = v081373[n];
    v303756 = ordinal_transform(vector(up_to,n,A002322(n)));
    A303756(n) = v303756[n];
    v322023 = rgs_transform(vector(up_to, n, [A081373(n), A303756(n)]));
    A322023(n) = v322023[n];