A372596 a(1)=-1; thereafter a(n) is (the number of terms that appear with a different frequency from that of a(n-1)) minus (the number of terms that appear with the same frequency).

-1, -1, -2, 1, 0, -1, 0, 3, 2, 1, 2, -1, 4, 7, 6, 5, 4, 1, 12, 7, 4, 9, 10, 9, 8, 11, 10, 7, 10, 5, 14, 17, 16, 15, 14, 15, 12, 9, 8, 11, 8, 5, 0, -5, 32, 31, 30, 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, 19, 18, 17, 36, 19, 34, 21, 32, 29, 26, 23, 20, 17, 16, 19

Offset

1,3

Links

Neal Gersh Tolunsky, Table of n, a(n) for n = 1..10000

Rémy Sigrist, PARI program.

Neal Gersh Tolunsky, Graph of first 200000 terms.

Example

Let t'(n) be the number of terms that appear with a different frequency from that of a(n-1) and t(n) be the number of remaining terms.
The resulting a(n) = t'(n) - t(n) are then:
   n  t'(n)  t(n) a(n)
  --  ----  ----  ----
   1     *     *    -1
   2     0     1    -1
   3     0     2    -2
   4     2     1     1
   5     2     2     0
   6     2     3    -1
   7     3     3     0
   8     5     2     3
   9     5     3     2
  10     5     4     1

Prog

(PARI) \\ See Links section.

Crossrefs

Cf. A372598, A350768, A363764.

Sequence in context: A116675 A123022 A072943 * A072175 A280712 A363926

Adjacent sequences: A372593 A372594 A372595 * A372597 A372598 A372599

Keyword

sign

Author

Neal Gersh Tolunsky, May 05 2024

Status

approved