Metadata
bibkey: hanna2024a375439
authors: Paul D. Hanna
year: 2024
title: "OEIS A375439, expansion of A(x) = x + x^2 + (2*A(x)^3 + A(x^3))/3"
doi: null
url: https://oeis.org/A375439
claim: "Expansion of g.f. A(x) satisfying A(x) = x + x^2 + (2*A(x)^3 + A(x^3))/3. Conjecture: a(n) is odd iff n is in A038754, which consists of numbers of the form 3^k and 2*3^k."
strata_touched:
- D5/S1/Recurrence/Invariants/CubicTernarySubstitutionParity
license: citation-only
triage: anchor
OEIS A375439
Paul D. Hanna’s entry defines the coefficients by the displayed functional equation and conjectures that the odd coefficients occur exactly at powers of three and twice powers of three. The sequence begins at index one; the formal generating series has constant coefficient zero.
Verified locator
- URL: https://oeis.org/A375439