A297895 Numbers that can be partitioned into squares of distinct integers whose reciprocals sum to 1.

1, 49, 200, 338, 418, 445, 486, 489, 530, 569, 609, 610, 653, 770, 775, 804, 845, 855, 898, 899, 939, 978, 1005, 1019, 1049, 1065, 1085, 1090, 1134, 1194, 1207, 1213, 1214, 1254, 1281, 1308, 1356, 1374, 1379, 1382, 1415, 1434, 1442, 1457, 1458, 1459, 1475, 1499, 1502, 1522, 1543, 1566, 1570, 1582

Offset: 1

Author

Max Alekseyev, Jan 08 2018

Keywords

• nonn

Comments

All integers > 8542 = A297896(1) belong to this sequence.

Examples

			49 = 2^2 + 3^2 + 6^2, where 1/2 + 1/3 + 1/6 = 1;
200 = 2^2 + 4^2 + 6^2 + 12^2, where 1/2 + 1/4 + 1/6 + 1/12 = 1;
338 = 2^2 + 3^2 + 10^2 + 15^2, where 1/2 + 1/3 + 1/10 + 1/15 = 1.
		

Links

• Max Alekseyev, Table of n, a(n) for n = 1..5000
• Max Alekseyev (2019). On partitions into squares of distinct integers whose reciprocals sum to 1. In: J. Beineke, J. Rosenhouse (eds.) The Mathematics of Various Entertaining Subjects: Research in Recreational Math, Volume 3, Princeton University Press, pp. 213-221. ISBN 978-0-691-18257-5 DOI:10.2307/j.ctvd58spj.18 Preprint arXiv:1801.05928 [math.NT], 2018.
• Max Alekseyev, List of all representable numbers in the interval [1,54533] and their representations (see Alekseyev 2019 paper for details)

Crossrefs

Cf. A051882, A051909, A052428, A297896, A303400.

Formula

For n >= 4496, a(n) = n + 4047.