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 A054253 a(n) = n + max{ a(i)*a(n-i) ; 1 <= i <= n-1 }, a(n) = n for n <= 2. 1
 1, 2, 5, 9, 15, 31, 52, 89, 164, 289, 479, 973, 1625, 2773, 5099, 8975, 15045, 30181, 50615, 86617, 159593, 281219, 469648, 946753, 1581150, 2698155, 4961354, 8732703, 14638814, 29366143, 49248426, 84278373, 155284022, 273626121, 456980910, 921190705, 1538473662 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Alois P. Heinz, Table of n, a(n) for n = 1..2000 EXAMPLE a(5) = 5 plus the maximum of {1*2,2*5} = 5+10=15. a(6) = 6 plus the maximum of {1*15,2*9,5*5} = 6+25=31. MAPLE A054253 := proc(n) local i, j; option remember; if n<=2 then n else j := 0; for i from 1 to n-1 do if procname(i)*procname(n-i) >= j then j := procname(i)*procname(n-i); end if; end do; n+j; end if; end proc; # second Maple program: a:= proc(n) option remember; n +`if`(n>2,       max(seq(a(i)*a(n-i), i=1..n/2)), 0)     end: seq(a(n), n=1..42);  # Alois P. Heinz, Apr 03 2020 MATHEMATICA a[n_] := a[n] = If[n <= 2, n, n + Max[a[#] a[n-#]& /@ Range[n-1]]]; Array[a, 33] (* Jean-François Alcover, Apr 03 2020 *) CROSSREFS Sequence in context: A176691 A339554 A274355 * A045649 A267694 A024519 Adjacent sequences:  A054250 A054251 A054252 * A054254 A054255 A054256 KEYWORD nonn AUTHOR N. J. A. Sloane, May 04 2000 EXTENSIONS More specific name and examples from M. F. Hasler, Dec 08 2009 and R. J. Mathar, Dec 09 2009 STATUS approved

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Last modified December 7 13:05 EST 2021. Contains 349581 sequences. (Running on oeis4.)