A298731 Number of distinct representations of n as a sum of four terms of A020330 (including 0), where order does not matter.
1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 1, 1, 0, 1, 1, 1, 1, 0, 1, 0, 2, 1, 0, 2, 0, 1, 2, 0, 1, 1, 2, 0, 1, 1, 0, 4, 1, 0, 2, 1, 1, 2, 1, 0, 3, 2, 1, 2, 1, 1, 3, 2, 0, 3, 2, 1, 4, 1, 1, 3, 2, 1, 3, 2, 1, 4, 2, 1, 3, 2, 1, 3, 2, 1, 4, 2, 1, 3, 1, 1, 4, 2, 1, 4, 2, 0, 4, 1, 1, 4, 2, 1, 3, 3, 0, 4, 1
Offset: 0
Keywords
Examples
For n = 45, the a(45) = 4 solutions are 45 = 15+15+15 = 36+3+3+3 = 15+10+10+10.
Links
- Amiram Eldar, Table of n, a(n) for n = 0..10000
- Parthasarathy Madhusudan, Dirk Nowotka, Aayush Rajasekaran and Jeffrey Shallit, Lagrange's Theorem for Binary Squares, in: I. Potapov, P. Spirakis and J. Worrell (eds.), 43rd International Symposium on Mathematical Foundations of Computer Science (MFCS 2018), Schloss Dagstuhl, 2018, pp. 18:1-18:14; arXiv preprint, arXiv:1710.04247 [math.NT], 2017-2018.
Programs
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Mathematica
v = Table[k + k * 2^Floor[Log2[k] + 1], {k, 0, 8}]; a[n_] := Length @ IntegerPartitions[n, {4}, v]; Table[a[n], {n, 0, v[[-1]]}] (* Amiram Eldar, Apr 09 2021 *)