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.

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A364495 Odd numbers k such that k divides A163511(k).

Original entry on oeis.org

1, 3, 9, 105, 429, 1365, 1617, 3887, 4235, 10829, 14025, 17745, 21125, 22627, 38025, 54587, 70805, 100555, 115159, 147875, 168751, 169065, 175769, 181447, 181545, 291525, 297297, 303875, 338675, 350987, 501787, 513825, 518035, 549081, 560947, 566865, 594473, 624169, 676039, 735875, 745147, 831875, 869193, 957125
Offset: 1

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Author

Antti Karttunen, Jul 27 2023

Keywords

Examples

			For n = 513825 = 3 * 5^2 * 13 * 17 * 31, A163511(n) = 13873275 = 3^4 * 5^2 * 13 * 17 * 31, so A163511(n)/n = 27 (which is an integer), and therefore 513825 is included in this sequence.
		

Crossrefs

Odd terms in A364494.
After 1, sequence A243071(A364965(n)), for n>=1, sorted into ascending order.
Cf. A163511.

Programs

  • PARI
    A005940(n) = { my(p=2, t=1); n--; until(!n\=2, if((n%2), (t*=p), p=nextprime(p+1))); t };
    A054429(n) = ((3<<#binary(n\2))-n-1);
    A163511(n) = if(!n,1,A005940(1+A054429(n)))
    A163511(n) = if(!n,1,my(p=2, t=1); while(n>1, if(!(n%2), (t*=p), p=nextprime(1+p)); n >>= 1); (t*p));
    isA364495(n) = ((n%2)&&!(A163511(n)%n));

A364295 Numbers k such that A292943(k) = A292944(k).

Original entry on oeis.org

1, 2, 3, 4, 6, 8, 9, 12, 16, 18, 24, 32, 36, 45, 48, 64, 72, 90, 96, 128, 144, 165, 180, 189, 192, 256, 288, 330, 360, 378, 384, 512, 576, 660, 720, 756, 768, 1024, 1152, 1320, 1440, 1512, 1536, 2048, 2304, 2640, 2880, 3024, 3072, 4096, 4608, 5280, 5760, 6048, 6144, 8192, 9216, 10560, 11520, 12096, 12288, 16384
Offset: 1

Views

Author

Antti Karttunen, Jul 26 2023

Keywords

Comments

If n is present, then 2*n is also present, and vice versa.
A007283 is included as a subsequence, because it gives the known fixed points of map n -> A163511(n).

Crossrefs

Subsequences: A000079, A007283, A029744, A364296 (odd terms).
Cf. also A364494, A364496.

Programs

Showing 1-2 of 2 results.