A038752 Earliest sequence where a(a(n))=number of partitions of n.

1, 1, 2, 3, 6, 11, 5, 56, 9, 22, 12, 7, 42, 14, 101, 526823, 17, 231, 19, 385, 21, 627, 30, 24, 1255, 26, 1958, 28, 3010, 31, 1002, 4565, 33, 8349, 35, 12310, 37, 17977, 39, 26015, 41, 37338, 77, 44, 63261, 46, 89134, 48, 124754, 50, 173525, 52, 239943, 54

Offset

0,3

Comments

From Georg Fischer, Feb 11 2021: (Start)

An algorithm may try to estimate terms a(n) = m for m = 0, 1, 2, ... as follows:

- for m <= n the partition property must be satisfied,

- m = n+1 must be accepted as the "earliest" new member,

- for any m > n (estimated or computed), a(m) can immediately be computed by a(m)=a(a(n))=p(n). (End)

Links

Table of n, a(n) for n=0..53.

Index entries for sequences of the a(a(n)) = 2n family

Example

a(5)=a(a(6))=11.

Crossrefs

Cf. A000041.

Sequence in context: A186408 A062527 A296444 * A125714 A361593 A247953

Adjacent sequences: A038749 A038750 A038751 * A038753 A038754 A038755

Keyword

nonn

Author

Henry Bottomley, May 03 2000

Extensions

a(15) corrected by Georg Fischer, Feb 15 2021

Status

approved