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A038235
Bottom line of 4-wave sequence A038197, also bisection of A006357.
1
1, 10, 85, 707, 5864, 48620, 403104, 3342081, 27708726, 229729153, 1904652103, 15791202736, 130922641160, 1085461206128, 8999406210929, 74612811302754, 618604325665341, 5128761469382475, 42521840081752984, 352542596245147348
OFFSET
0,2
FORMULA
Let v(4)=(1, 1, 1, 1), let M(4) be the 4 X 4 matrix m(i, j) = min(i, j); then a(n) = max(v(4)*M(4)^n). - Benoit Cloitre, Oct 03 2002
From Floor van Lamoen, Sep 13 2006: (Start)
a(n) = 10a(n-1) - 15a(n-2) + 7a(n-3) - a(n-4).
G.f.: 1/(1 - 10x + 15x^2 - 7x^3 + x^4). (End)
MATHEMATICA
LinearRecurrence[{10, -15, 7, -1}, {1, 10, 85, 707}, 20] (* Harvey P. Dale, Nov 24 2019 *)
PROG
(PARI) k=4; M(k)=matrix(k, k, i, j, min(i, j)); v(k)=vector(k, i, 1); a(n)=vecmax(v(k)*M(k)^n)
CROSSREFS
Sequence in context: A361285 A144639 A233667 * A354390 A354318 A346946
KEYWORD
nonn,easy
STATUS
approved