cp's OEIS Frontend

A341286 Numbers k such that k plus the sum of the fifth powers of the digits of k is a cube.

%I A341286 #37 Jul 19 2022 16:20:50
%S A341286 0,2435,3403,5625,8781,11140,22664,23325,32908,33346,34822,41332,
%T A341286 58555,99180,103925,109272,133118,136386,145263,170740,180105,182142,
%U A341286 194261,207459,208813,228224,249945,251991,266080,305840,341539,351824,359720,372287,380064,415434
%N A341286 Numbers k such that k plus the sum of the fifth powers of the digits of k is a cube.
%e A341286 2435 is a term since 2435 + 2^5 + 4^5 + 3^5 + 5^5 = 19^3;
%e A341286 3403 is a term since 3403 + 3^5 + 4^5 + 0^5 + 3^5 = 17^3.
%p A341286 filter:= proc(n) local x, d;
%p A341286   x:= n + add(d^5, d = convert(n, base, 10));
%p A341286   surd(x, 3)::integer
%p A341286 end proc:
%p A341286 select(filter, [$0..10^5]); # _Robert Israel_, Feb 09 2021
%t A341286 Select[Range[0, 500000], IntegerQ@ Power[# + Total[IntegerDigits[#]^5], 1/3] &] (* _Michael De Vlieger_, Feb 22 2021 *)
%t A341286 Select[Range[0,416000],IntegerQ[Surd[#+Total[IntegerDigits[#]^5],3]]&] (* _Harvey P. Dale_, Jul 19 2022 *)
%o A341286 (PARI) isok(k) = ispower(k+vecsum(apply(x->x^5, digits(k))), 3); \\ _Michel Marcus_, Feb 09 2021
%o A341286 (Python)
%o A341286 from sympy import integer_nthroot
%o A341286 def powsum(n): return sum(int(d)**5 for d in str(n))
%o A341286 def ok(n): return integer_nthroot(n + powsum(n), 3)[1]
%o A341286 def aupto(lim):
%o A341286   alst = []
%o A341286   for k in range(lim+1):
%o A341286     if ok(k): alst.append(k)
%o A341286   return alst
%o A341286 print(aupto(415434)) # _Michael S. Branicky_, Feb 22 2021
%Y A341286 Cf. A055014 (sum of 5th powers of digits).
%K A341286 base,nonn,less
%O A341286 1,2
%A A341286 _Will Gosnell_, Feb 08 2021
%E A341286 More terms from _Michel Marcus_, Feb 09 2021
%E A341286 a(1)=0 prepended by _Michael S. Branicky_, Feb 22 2021