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A185673
Least number k having n representations as the sum of the minimal number of biquadrates A002377(k).
1
1, 259, 518, 777, 3402, 3645, 3726, 7045, 7243, 12683, 16441, 13723, 13792, 21631, 20202, 23002, 24135, 27162, 28870, 28215, 33230, 39629, 36510, 41561, 43241, 29563, 47401, 41310, 47150, 47790, 56749, 43962, 48750, 62681, 65069, 50442
OFFSET
1,2
COMMENTS
This sequence is not monotonically increasing: a(21)=33230 > a(26)=29563.
LINKS
Eric Weisstein's World of Mathematics, Waring's Problem.
EXAMPLE
a(1) = 1 since 1 = 1^4 (1 way with minimal representation)
a(2) = 259 since 259 = 1^4 + 1^4 + 1^4 + 4^4 = 2^4 + 3^4 + 3^4 + 3^4 (2 ways with minimal representation)
a(3) = 518 since 518 = 1^4 + 1^4 + 1^4 + 1^4 + 1^4 + 1^4 + 4^4 + 4^4 = 1^4 + 1^4 + 1^4 + 2^4 + 3^4 + 3^4 + 3^4 + 4^4 = 2^4 + 2^4 + 3^4 + 3^4 + 3^4 + 3^4 + 3^4 + 3^4 (3 ways with minimal representation)
MATHEMATICA
t=Table[r=PowersRepresentations[n, 19, 4]; Sort[Tally[19-Count[#, 0]&/@r]][[1, 2]], {n, 800}]; u=Union[t]; c=Complement[Range[Max[u]], u]; If[c=={}, mx=u[[-1]], mx=c[[1]]-1]; Flatten[Table[Position[t, n, 1, 1], {n, mx}]]
CROSSREFS
Cf. A002377.
Sequence in context: A101521 A207060 A037987 * A082788 A043376 A038480
KEYWORD
nonn
AUTHOR
Martin Renner, Feb 09 2011
EXTENSIONS
a(10)-a(36) from Alois P. Heinz, Feb 10 2011
STATUS
approved