疑難找規律

85815

（這道題不適合發到邏輯區因為我覺得這不是人做的題）
朋友給的題，據說是某一屆IMO的神奇找規律。
0,1,3,2,5,4,6,3,7,6,8,5,10,7,9,4，？
網上沒答案（至少我沒找到）
@天馬行空

22568

@我作甚..
下一項是9527,因為通項公式是

1. 173611-(138484294591/240240)*n+(93077/20922789888000)*n^16-(405811/242611200)*n^13+(43745389/1046139494400)*n^14-(332897/523069747200)*n^15-(131188972409/914457600)*n^9+(95142558001/7315660800)*n^10-(73271267/82114560)*n^11+(5233364797/114960384000)*n^12+(165599910762199/201801600)*n^2-(223117770655471/330220800)*n^3+(17638785137200319/48432384000)*n^4-(14102969295311/102643200)*n^5+(217097008707211/5748019200)*n^6-(4052785211849/522547200)*n^7+(176656363444427/146313216000)*n^8

復制代碼

嘛..言歸正傳..
A326730
oeis都有的東西乃告訴我網上搜不到?

0, 0, 3, 1, 5, 7, 4, 3, 9, 11, 8, 15, 14, 9, 10, 7, 17, 19, 16, 23, 22, 17, 18, 31, 26, 29, 30, 19, 24, 21, 22, 15, 33, 35, 32, 39, 38, 33, 34, 47, 42, 45, 46, 35, 40, 37, 38, 63, 50, 53, 54, 59, 48, 61, 62, 39, 60, 49, 50, 43, 52, 45, 46, 31, 65, 67, 64, 71, 70, 65, 66, 79, 74, 77, 78, 67, 72, 69, 70, 95, 82, 85, 86, 91, 80, 93, 94, 71, 92, 81, 82, 75, 84, 77, 78, 127, 98, 101, 102, 107, 96

Problem 5 of IMO 2019