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A278817
The least t such that there exists a sequence n = b_1 < b_2 < ... < b_t = A277278(n) such that b_1 + b_2 +...+ b_t is a perfect square.
1
1, 1, 3, 2, 1, 5, 2, 2, 6, 1, 3, 3, 2, 4, 3, 3, 1, 2, 4, 3, 3, 5, 2, 2, 2, 1, 3, 4, 4, 2, 2, 2, 3, 4, 4, 6, 1, 5, 3, 2, 2, 5, 5, 5, 3, 3, 3, 3, 2, 1, 6, 6, 3, 3, 3, 3, 6, 6, 2, 2, 2, 4, 4, 3, 1, 7, 7, 4, 4, 2, 2, 2, 3, 3, 3, 5, 5, 5, 5, 4, 2, 1, 2, 2, 2, 5, 5
OFFSET
0,3
COMMENTS
a(n) = 1 if and only if n is square.
a(n) = 2 if and only if A277278(n) = A278818(n).
EXAMPLE
a(0) = 1 via 0 = 0^2
a(1) = 1 via 1 = 1^2
a(2) = 3 via 2 + 3 + 4 = 3^2
a(3) = 2 via 3 + 6 = 3^2
a(4) = 1 via 4 = 2^2
a(5) = 5 via 5 + 6 + 7 + 8 + 10 = 6^2
a(6) = 2 via 6 + 10 = 4^2
CROSSREFS
KEYWORD
nonn
AUTHOR
Peter Kagey, Nov 28 2016
STATUS
approved