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A281966
Number of sets of exactly n positive integers <= n+3 having a square element sum.
2
1, 2, 2, 3, 5, 6, 7, 10, 13, 14, 16, 21, 25, 24, 31, 37, 37, 40, 50, 55, 51, 64, 74, 69, 77, 92, 95, 89, 111, 122, 110, 127, 146, 145, 139, 171, 181, 161, 191, 213, 202, 203, 243, 250, 222, 270, 292, 264, 285, 328, 326, 296, 362, 381, 335, 383, 425, 407, 388
OFFSET
0,2
LINKS
FORMULA
a(n) = A281871(n+3,n).
EXAMPLE
a(3) = 3: {1,2,6}, {1,3,5}, {2,3,4}.
a(4) = 5: {1,2,6,7}, {1,3,5,7}, {1,4,5,6}, {2,3,4,7}, {2,3,5,6}.
a(5) = 6: {1,2,3,4,6}, {1,3,6,7,8}, {1,4,5,7,8}, {2,3,5,7,8}, {2,4,5,6,8}, {3,4,5,6,7}.
CROSSREFS
A diagonal of A281871.
Sequence in context: A266746 A373220 A096981 * A276431 A308272 A035541
KEYWORD
nonn,look
AUTHOR
Alois P. Heinz, Feb 03 2017
STATUS
approved