OFFSET
1,1
COMMENTS
A242192(k) gives number of occurrences of k. - Reinhard Zumkeller, May 07 2014
See A300564 for the list of values without duplicates. - M. F. Hasler, Apr 16 2018
LINKS
Lars Blomberg, Table of n, a(n) for n = 1..2241
FORMULA
c = sqrt(sqrt(a^2+b^3)) is an integer.
EXAMPLE
6 is in the sequence because 6^4 = 28^2 + 8^3.
72 is in the sequence twice because 72^4 = 1728^2 + 288^3 = 4941^2 + 135^3.
MATHEMATICA
f[n_] := f[n] = Module[{a}, Array[(a = Sqrt[n^4 - #^3]; If[ IntegerQ@ a && a > 0, {a, #}, Sequence @@ {}]) &, Floor[n^(4/3)]]];; k = 1; lst = {}; While[k < 3001, If[ f[k] != {}, AppendTo[lst, k]; Print[{k, f[k]}]]; k++]; s = Select[ Range[3000], f@# != {} &]; l = Length@ f@ # & /@ s; Flatten[ Table[ s[[#]], {l[[#]]}] & /@ Range@ Length@ s] (* Robert G. Wilson v, May 06 2014 *)
PROG
(Haskell)
a242183 n = a242183_list !! (n-1)
a242183_list = concatMap (\(r, x) -> take r [x, x..]) $
zip a242192_list [1..]
-- Reinhard Zumkeller, May 07 2014
CROSSREFS
KEYWORD
nonn
AUTHOR
Lars Blomberg, May 06 2014
STATUS
approved