A281970 Number of sets of exactly n positive integers <= n+7 having a square element sum.
1, 2, 6, 15, 34, 71, 134, 238, 405, 660, 1030, 1559, 2310, 3336, 4691, 6500, 8886, 11899, 15709, 20584, 26624, 33926, 42974, 54080, 67172, 82800, 101787, 124031, 149660, 180251, 216171, 256730, 303737, 359036, 421356, 491196, 572792, 665539, 767239, 883380
Offset: 0
Keywords
Examples
a(3) = 15: {1,2,6}, {1,3,5}, {1,5,10}, {1,6,9}, {1,7,8}, {2,3,4}, {2,4,10}, {2,5,9}, {2,6,8}, {3,4,9}, {3,5,8}, {3,6,7}, {4,5,7}, {6,9,10}, {7,8,10}.
Links
- Alois P. Heinz, Table of n, a(n) for n = 0..1000
Crossrefs
A diagonal of A281871.
Formula
a(n) = A281871(n+7,n).