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 A255018 Smallest number that is the sum of 3 nonnegative cubes in exactly n ways. 1
 4, 0, 216, 5104, 13896, 161568, 1259712, 2016496, 2562624, 14926248, 58995000, 34012224, 150547032, 471960000, 119095488, 1259712000, 952763904, 5159780352, 3974344704, 2176782336 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 LINKS EXAMPLE a(0) = 4 because the smallest number that cannot be represented as a sum of 3 nonnegative cubes is 4. a(1) = 0 is the sum of three 0's. a(2) = 216 = 3^3 + 4^3 + 5^3 = 6^3 + 0 + 0. a(3) = 5104 = 1 + 12^3 + 15^3 = 2^3 + 10^3 + 16^3 = 9^3 + 10^3 + 15^3. PROG (Python) TOP = 60000000 a = [0]*TOP for b in range(TOP):   b3 = b**3   if b3*3>=TOP: break for c in range(b, TOP):     c3 = b3 + c**3     if c3>=TOP: break for d in range(c, TOP):       res = c3 + d**3       if res>=TOP: break       #if res==5104: print b, c, d       a[res] += 1 m = max(a) print m r = [-1] * (m+1) for i in range(TOP):     if r[a[i]]==-1:  r[a[i]]=i print r CROSSREFS Cf. A000578, A000446, A011541, A025418, A025419. Sequence in context: A138734 A265596 A119010 * A176050 A099841 A013452 Adjacent sequences:  A255015 A255016 A255017 * A255019 A255020 A255021 KEYWORD nonn,more AUTHOR Alex Ratushnyak, Feb 25 2015 STATUS approved

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Last modified May 31 13:01 EDT 2020. Contains 334748 sequences. (Running on oeis4.)