A307730 a(n) = A307720(n) * A307720(n+1).

1, 2, 2, 3, 3, 3, 6, 4, 4, 4, 4, 6, 6, 6, 6, 6, 9, 9, 9, 9, 9, 9, 9, 9, 9, 12, 8, 8, 8, 8, 8, 8, 8, 8, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 15, 5, 5, 5, 5, 5, 7, 7, 7, 7, 7, 7, 7, 14, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 14, 14, 14, 14, 14, 14, 14

Offset

1,2

Comments

For all positive integers n, n appears n times.

Links

Rémy Sigrist, Table of n, a(n) for n = 1..25000

Rémy Sigrist, Scatterplot of the first 10000000 terms

Rémy Sigrist, PARI program for A307730

N. J. A. Sloane, Table of n, a(n) for n = 1..999999

Example

The first terms in this sequence and in A307720 are:
  n   a(n)  A307720(n)
  --  ----  ----------
   1     1           1
   2     2           1
   3     2           2
   4     3           1
   5     3           3
   6     3           1
   7     6           3
   8     4           2
   9     4           2
  10     4           2

Prog

(PARI) See Links section.
(Python)
from itertools import islice
from collections import Counter
def A307730(): # generator of terms. Greedy algorithm
    c, b = Counter(), 1
    while True:
        k, kb = 1, b
        while c[kb] >= kb:
            k += 1
            kb += b
        c[kb] += 1
        b = k
        yield kb
A307730_list = list(islice(A307730(), 100)) # Chai Wah Wu, Oct 21 2021

Crossrefs

Cf. A002024, A088178, A307720.

Sequence in context: A078462 A239518 A293924 * A169618 A175454 A157501

Adjacent sequences: A307727 A307728 A307729 * A307731 A307732 A307733

Keyword

nonn,hear

Author

Rémy Sigrist, Apr 25 2019

Status

approved