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.

A236837 The greatest inverse of A234741: a(n) = the largest k such that A234741(k) = n, and 0 if no such k exists.

Original entry on oeis.org

0, 1, 2, 3, 4, 9, 6, 7, 8, 21, 18, 11, 12, 13, 14, 27, 16, 81, 42, 19, 36, 49, 22, 39, 24, 0, 26, 63, 28, 33, 54, 31, 32, 93, 162, 91, 84, 37, 38, 99, 72, 41, 98, 43, 44, 189, 78, 47, 48, 77, 0, 243, 52, 57, 126, 0, 56, 117, 66, 59, 108, 61, 62, 147, 64, 441, 186, 67, 324, 121
Offset: 0

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Author

Antti Karttunen, Jan 31 2014

Keywords

Comments

A234741(a(n)) = n, unless n is in A236834, in which case a(n)=0.
For all n, a(n) <= A234742(n). A236850 gives such k that a(k) = A234742(k).
If n is in A236835, a(n) > A236836(n), otherwise a(n) = A236836(n).
a(2^n) = 2^n.
a(2n) = 2*a(n).

Crossrefs

A236834 gives the positions of zeros.
Differs from A235042 and A234742 for the first time at n=25, where a(25)=0 but A235042(25)=5 and A234742(25)=25.
Cf. A236836 (the least inverse of A234741).