0和1是三角数、正方形数和五边形数。
推测a(n)总是正的——这是Sun(2009)的推测1.1中的推测之一-N.J.A.斯隆2014年4月1日
用k种方式表示的最小数,k>=1:0,3,1,5,10,19,15,22,31,51,61,37,82,71,126,96,92,136,162,187,206,276,191,261,236,247,317,302,401,292,422,547,456,544,551,612,591,577,521,666,742,726,682,877,796,1052,961,1046,1171,1027。A275999型.
用k种方式表示的最大数(推测),k>=1:0,18,168,78,243,130,553,455,515,658,865,945,633,1918,2258,1385,1583,2828,2135,2335,2785,4533,3168,3478,2790,3868,4193,7328,4953,5278,6390,8148,8015,4585,9160,10485,7613,12333,12025,10178,9923,9720,12558,11340,17420,11753、14893、16155、, 16415, 14343, ..., .
以k>=1方式表示的数字推测列表:
1: 0;
2: 3, 18;
3: 1, 2, 4, 8, 9, 13, 14, 35, 98, 168;
4: 5, 6, 7, 21, 25, 30, 34, 39, 43, 48, 63, 78;
5: 10, 11, 12, 17, 20, 23, 28, 33, 69, 193, 203, 230, 243;
6: 19, 24, 32, 44, 53, 55, 74, 90, 111, 130;
7: 15, 16, 27, 29, 40, 46, 56, 60, 62, 68, 73, 84, 85, 95, 108, 113, 123, 135, 139, 163, 165, 273, 553;
8: 22, 26, 42, 45, 47, 49, 59, 65, 83, 88, 89, 93, 112, 119, 125, 134, 140, 144, 186, 205, 233, 244, 320, 405, 455;
9: 31, 36, 38, 41, 50, 52, 58, 100, 109, 124, 160, 214, 249, 308, 358, 515; ..., .