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A375744
Numbers that are the sum of 4 but no fewer nonzero squares and admit a representation with 4 distinct squares.
0
39, 63, 71, 79, 87, 95, 111, 119, 127, 135, 143, 151, 156, 159, 167, 175, 183, 191, 199, 207, 215, 223, 231, 239, 247, 252, 255, 263, 271, 279, 284, 287, 295, 303, 311, 316, 319, 327, 335, 343, 348, 351, 359, 367, 375, 380, 383, 391, 399, 407, 415, 423, 431
OFFSET
1,1
COMMENTS
Intersection of A004215 and A004433.
EXAMPLE
39 is a term, since it requires 4 squares to be represented and admits the representation 39 = 5^2 + 3^2 + 2^2 + 1^2.
30 is not a term, although it can be represented as a sum of 4 different squares 30 = 4^2+ 3^2 + 2^2 + 1^2 also admits a representation as a sum of 3 squares: 30 = 5^2 + 2^2 + 1^2.
7 is not a term, since although it requires 4 squares to be represented as follows 7 = 2^2 + 1^2 + 1^2 + 1^2, it is noted that 1 is used on more than one occasion.
CROSSREFS
Sequence in context: A043176 A043956 A090876 * A165461 A020166 A046448
KEYWORD
nonn
AUTHOR
Gonzalo Martínez, Aug 26 2024
STATUS
approved