A390943 Entries that keep growing, in the map initialized with T[1] = 1 and subsequently updated using T[v] := k + (T[v] if defined else 0), for all key-value pairs (k,v) in the map T at a given iteration.

1, 2, 4, 24, 28, 30, 32, 64, 88, 128, 132, 134, 268, 416, 1920, 3712, 7424

Offset

1,2

Comments

This sequence is finite. All other entries T[k] necessarily reach one of these values at a given iteration and remain constant thereafter.

Gareth McCaughan confirms that the list of these 17 terms is complete.

Links

Table of n, a(n) for n=1..17.

Prog

(Python)
A390939(999); A390943 = sorted(k for k, v in A390939.T.items() if v > 9999)
# check that for all keys not in A390943, the value is in S:
all(k in A390943 or v in A390943 for k, v in A390939.T.items()) # => True

Crossrefs

Cf. A390939 (main entry for this and related sequences).

Sequence in context: A090591 A098656 A138611 * A171459 A240558 A163896

Adjacent sequences: A390940 A390941 A390942 * A390944 A390945 A390946

Keyword

nonn,fini,full

Author

M. F. Hasler, Nov 25 2025

Status

approved