A047720 - OEIS

%I #10 Jul 07 2018 01:50:31

%S 9,24,39,54,69,89,104,119,134,144,149,169,184,199,209,214,229,249,264,

%T 279,294,309,329,344,359,374,384,389,404,409,424,439,449,454,469,484,

%U 489,504,519,534,549,564,569,579,584,599,614,624,633,649,664,679,694

%N Numbers that are the sum of 9 but no fewer nonzero fourth powers.

%H David A. Corneth, <a href="/A047720/b047720.txt">Table of n, a(n) for n = 1..16848</a> (first terms <= 200000)

%o (PARI) upto(n)={my(e=9); my(s=sum(k=1, sqrtint(sqrtint(n)), x^(k^4)) + O(x*x^n)); my(p=s^e, q=(1 + s)^(e-1)); select(k->polcoeff(p,k) && !polcoeff(q,k), [1..n])} \\ _Andrew Howroyd_, Jul 06 2018

%Y Cf. A000583, A002377, A003343.

%K nonn

%O 1,1

%A Arlin Anderson (starship1(AT)gmail.com)