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A239247
Numbers n such that n^4 can be written as a sum of five distinct positive 4th powers.
1
15, 30, 35, 45, 55, 60, 65, 70, 75, 85, 89, 90, 95, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 165, 170, 175, 178, 180, 185, 190, 195, 205, 210, 215, 220, 225, 230, 233, 235, 240, 245, 250, 255, 260, 265, 267, 270, 275, 280, 285, 290, 295, 300
OFFSET
1,1
COMMENTS
Every multiple of a term is a term.
LINKS
Lars Blomberg, Primitive solutions for terms < 10000. Only the first solution found for each term is included.
Eric Weisstein's World of Mathematics, Diophantine Equation 4th Powers.
FORMULA
a(1) = A130022(4).
EXAMPLE
15^4 = 4^4 + 6^4 + 8^4 + 9^4 + 14^4.
35^4 = 4^4 + 21^4 + 22^4 + 26^4 + 28^4.
55^4 = 2^4 + 13^4 + 16^4 + 44^4 + 48^4.
65^4 = 1^4 + 8^4 + 12^4 + 32^4 + 64^4.
85^4 = 2^4 + 13^4 + 32^4 + 34^4 + 84^4.
89^4 = 10^4 + 35^4 + 52^4 + 60^4 + 80^4.
95^4 = 6^4 + 48^4 + 66^4 + 67^4 + 78^4.
115^4 = 4^4 + 31^4 + 48^4 + 58^4 + 112^4.
125^4 = 8^4 + 11^4 + 26^4 + 84^4 + 118^4.
145^4 = 2^4 + 23^4 + 46^4 + 52^4 + 144^4.
155^4 = 6^4 + 39^4 + 88^4 + 96^4 + 144^4.
185^4 = 2^4 + 38^4 + 62^4 + 87^4 + 182^4.
205^4 = 4^4 + 133^4 + 142^4 + 146^4 + 156^4.
215^4 = 4^4 + 26^4 + 127^4 + 174^4 + 176^4.
233^4 = 40^4 + 65^4 + 94^4 + 150^4 + 220^4.
235^4 = 9^4 + 52^4 + 148^4 + 184^4 + 194^4.
PROG
(PARI) isok(n) = {ret = 0; for (x=1, sqrtnint(n^4\5, 4), for (y=x+1, sqrtnint((n^4 - x^4)\4, 4), for (z=y+1, sqrtnint((n^4 - x^4 - y^4)\3, 4), for (t=z+1, sqrtnint((n^4 - x^4 - y^4 - z^4)\2, 4), for (u=t+1, sqrtnint((n^4 - x^4 - y^4 - z^4 - t^4), 4), if (x^4+y^4+z^4+t^4+u^4 == n^4, print(n, ": ", x, ", ", y, ", ", z , ", ", t, ", ", u); ret = 1; ); ); ); ); ); ); return (ret); }
CROSSREFS
Cf. A130022, A003828 (three 4th powers), A096739 (four 4th powers).
Sequence in context: A033898 A051967 A162592 * A291045 A079877 A215951
KEYWORD
nonn
AUTHOR
Michel Marcus, Mar 13 2014
EXTENSIONS
Missing terms 15 and its multiples found by Alois P. Heinz, Mar 14 2014
More examples from Michel Marcus, Mar 18 2014
More terms from Lars Blomberg, Apr 05 2014
STATUS
approved