A292113 List of numbers n such that A039654(n) reaches a new record high.

2, 3, 4, 8, 9, 32, 36, 64, 81, 100, 121, 144, 228, 256, 300, 400, 441, 468, 800, 1200, 2964, 5202, 5408, 6084, 6400, 7500, 8100, 9216, 24556, 28092, 31329, 32176, 32400, 37296, 49017, 49152, 57600, 72156, 80400, 83161, 86352, 88200, 133200

Offset

1,1

Comments

Naively, one might have expected these numbers to have some other distinguishing property (primorials, perhaps), but that seems not to be the case.

Except for 3 of the listed terms, a(n)-1 or a(n)+1 has at most 2 prime divisors. The same is true for many of the terms themselves, often of the form 2^k, 3^k, 2^k*3^k' or 2^k*5^k'. (Factorization of the terms: 2, 3, 2^2, 2^3, 3^2, 2^5, 2^2*3^2, 2^6, 3^4, 2^2*5^2, 11^2, 2^4*3^2, 2^2*3*19, 2^8, 2^2*3*5^2, 2^4*5^2, 3^2*7^2, 2^2*3^2*13, 2^5*5^2, ...) - M. F. Hasler, Sep 25 2017

Links

Hugo Pfoertner, Table of n, a(n) for n = 1..56

Prog

(PARI) m=-n=1; until(print1(n", "), until(A039654(n++)>m, ); m=A039654(n)) \\ M. F. Hasler, Sep 25 2017

Crossrefs

Cf. A039654, A039655, A292112.

Sequence in context: A126312 A126298 A175404 * A082224 A030478 A118252

Adjacent sequences: A292110 A292111 A292112 * A292114 A292115 A292116

Keyword

nonn

Author

N. J. A. Sloane, Sep 22 2017

Status

approved