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.

A358215 Numbers k for which there is no prime p such that p^p divides the arithmetic derivative of k, A003415(k).

Original entry on oeis.org

2, 3, 5, 6, 7, 9, 10, 11, 13, 14, 17, 18, 19, 21, 22, 23, 25, 26, 29, 30, 31, 33, 34, 37, 38, 41, 42, 43, 45, 46, 47, 49, 50, 53, 57, 58, 59, 61, 62, 63, 65, 66, 67, 69, 70, 71, 73, 74, 75, 77, 78, 79, 82, 83, 85, 86, 89, 90, 93, 94, 97, 98, 99, 101, 102, 103, 105, 106, 107, 109, 110, 113, 114, 117, 118, 121, 122, 125
Offset: 1

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Author

Antti Karttunen, Nov 24 2022

Keywords

Comments

Numbers k such that A003415(k) is in A048103.

Crossrefs

Complement of {1} U A327929. Positions of 0's in A341996 (after the two initial zeros). Positions of 1's in A341997.
Subsequence of A048103.
Subsequences: A099308 (apart from its two initial terms), A328393, A358221.
Cf. A003415, A327934, A351088, A359550, A368915 (characteristic function).

Programs

  • PARI
    A003415(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]/f[i, 1]));
    A359550(n) = { my(f = factor(n)); prod(k=1, #f~, (f[k, 2]A368915(n) = ((n>1)&&A359550(A003415(n)));
    isA358215(n) = A368915(n);