A270306 Smallest number which is representable as a sum of n but no fewer consecutive nonnegative integers, or 0 for n > 1 if no such number exists.

0, 1, 6, 10, 20, 0, 28, 44, 0, 0, 88, 0, 104, 0, 0, 136, 272, 0, 304, 0, 0, 0, 368, 0, 0, 0, 0, 0, 464, 0, 496, 592, 0, 0, 0, 0, 1184, 0, 0, 0, 1312, 0, 1376, 0, 0, 0, 1504, 0, 0, 0, 0, 0, 1696, 0, 0, 0, 0, 0, 1888, 0, 1952, 0, 0, 2144, 0, 0, 4288, 0, 0, 0, 4544

Offset: 1

Author

Martin Renner, Mar 14 2016

Keywords

• nonn

Examples

			a(2) = 1 = 0 + 1 (two but no fewer terms)
a(3) = 6 = 1 + 2 + 3 (three but no fewer terms)
a(4) = 10 = 1 + 2 + 3 + 4 (four but no fewer terms)
a(5) = 20 = 2 + 3 + 4 + 5 + 6 (five but no fewer terms)
a(6) = 0, since no number needs six but no fewer terms
a(7) = 28 = 1 + 2 + 3 + 4 + 5 + 6 + 7 (seven but no fewer terms)
		

Links

• Ray Chandler, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A138591, A163172, A270296 to A270303.

Formula

a(A111774(n)) = 0.

a(A174090(n)) = A163172(n).