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A036465
If n^2 = Sum_{i} b(i)^2 for positive integers b(i) < n, then a(n) is the maximum value of min(b(i)).
1
1, 1, 2, 3, 3, 2, 4, 4, 6, 6, 6, 5, 7, 9, 8, 8, 9, 8, 12, 8, 12, 8, 12, 15, 13, 12, 14, 20, 18, 14, 16, 18, 17, 21, 18, 14, 19, 19, 24, 23, 21, 18, 24, 27, 23, 20, 24, 23, 30, 24, 26, 28, 27, 33, 28, 28, 40, 30, 36, 28, 31, 34, 32, 39, 36, 31, 34, 35, 42, 30
OFFSET
2,3
LINKS
EXAMPLE
a(9) = 4 since 9^2 = 7^2 + 4^2 + 4^2.
MAPLE
b:= proc(n, i) option remember; (s-> `if`(i=1, 1,
`if`(s>=n and issqr(n), isqrt(n), max(
`if`(s>n, 0, b(n-s, i)), b(n, i-1)))))(i^2)
end:
a:= n-> b(n^2, n-1):
seq(a(n), n=2..75); # Alois P. Heinz, Nov 03 2020
MATHEMATICA
b[n_, i_] := b[n, i] = Function[s, If[i == 1, 1,
If[s >= n && IntegerQ@Sqrt[n], Sqrt[n], Max[
If[s > n, 0, b[n-s, i]], b[n, i-1]]]]][i^2];
a[n_] := b[n^2, n-1];
Table[a[n], {n, 2, 75}] (* Jean-François Alcover, May 08 2022, after Alois P. Heinz *)
CROSSREFS
Sequence in context: A373345 A376698 A308284 * A265339 A182865 A131469
KEYWORD
nonn
EXTENSIONS
Title improved by Sean A. Irvine, Nov 03 2020
STATUS
approved