A364572 Starting from k=7, each subsequent term is the next larger odd k such that A005940(k) >= k and the ratio A005940(k)/k is nearer to 1.0 than for any previous k in the sequence.

7, 19, 321, 139307, 262365, 264245, 528577

Offset

1,1

Links

Table of n, a(n) for n=1..7.

Example

     k   A005940(k)   A005940(k)/k  A005940(k)-k
     7         9      1.285714286        2
    19        21      1.105263158        2
   321       323      1.006230530        2
139307    139965      1.004723381      658
262365    263375      1.003849599     1010
264245    264845      1.002270620      600
528577    528581      1.000007567        4.

Prog

(PARI) print1(7, ", "); r = A005940(7)/7; forstep(n=7, 1+(2^26), 2, t=A005940(n)/n; if(t>=1 && t < r, r=t; print1(n, ", ")))

Crossrefs

Cf. A005940.

Cf. also A364573, A364576.

Sequence in context: A331404 A191624 A221740 * A335990 A359636 A330875

Adjacent sequences: A364569 A364570 A364571 * A364573 A364574 A364575

Keyword

nonn,more

Author

Antti Karttunen, Aug 06 2023

Status

approved