1,2

We know that only the entries T[k] with k listed in A390943 continue to grow, all other entries remain constant after reaching one of the values listed in A390943, the largest of which is 7424. Thus, once M(r) = min { T[k] ; k in A390943 } has grown beyond 7472, we know that M(r) is the smallest entry that can be added to the map T at and after that iteration r.

We also know that M(r) equals the value of T[3712] from that moment on.

Therefore we also know that the terms of this sequence are eventually exactly the values reached by T[3712], which are of the form 961*2^n.

a(n) = 961*2^(n-17) for n >= 22.

(Python)

# get a[n-1] as a(n) (1-indexed) and extrapolate by doubling the last term:

class seq(list):__call__=lambda s, n: s[-1]<< n-len(s) if n>len(s) else s[n-1]

_, m = A390939(999), A390939.T[3712] # compute enough terms; get current M

A390941 = seq([an for an in A390939.terms[::-1] if an < m and (m:=an)][::-1])

Cf. A390939 (main entry), A390943 (limiting values and keys of unbounded entries).

Sequence in context: A319575 A318609 A195333 * A106274 A204661 A284919

Adjacent sequences: A390938 A390939 A390940 * A390942 A390943 A390944

nonn,easy

M. F. Hasler, Nov 24 2025

approved