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.

A262513 Numbers where A049820 takes a unique value; numbers n for which A060990(A049820(n)) = 1.

Original entry on oeis.org

5, 6, 7, 8, 11, 14, 17, 18, 20, 22, 23, 24, 27, 32, 34, 35, 40, 43, 46, 47, 50, 51, 57, 58, 61, 65, 72, 73, 77, 79, 81, 84, 86, 87, 88, 92, 93, 94, 96, 97, 98, 99, 101, 102, 103, 105, 107, 114, 116, 119, 120, 123, 125, 130, 135, 137, 143, 151, 154, 155, 158, 160, 163, 164, 173, 175, 177, 179, 184, 187, 191, 193, 194, 197, 198, 200, 203, 204, 206, 209, 210, 212
Offset: 1

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Author

Antti Karttunen, Sep 25 2015

Keywords

Comments

Sequence A262512 sorted into ascending order.
Numbers n such that there is no other number k for which A049820(k) = A049820(n).

Crossrefs

Cf. A262509 (a subsequence).

Programs

  • Mathematica
    lim = 212; s = Table[n - DivisorSigma[0, n], {n, 2 lim + 3}]; t = Length@ Position[s, #] & /@ Range[0, lim]; Position[t[[# + 1]] & /@ Take[s, lim], 1] // Flatten (* Michael De Vlieger, Sep 29 2015, after Wesley Ivan Hurt at A049820 *)