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A100013号 |
| n!中质数因子的个数+7(以倍数计算)。 |
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1
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3, 3, 2, 1, 1, 1, 1, 3, 3, 3, 3, 2, 3, 3, 4, 2, 2, 3, 3, 5, 5, 5, 3, 4, 3, 2, 4, 5, 5, 4, 7, 6, 4, 4, 7, 2, 5, 4, 7, 4, 5, 3, 4, 6, 5, 4, 3, 3, 5, 6, 3, 5, 6, 3, 3, 7, 4, 5, 5, 2, 4, 4, 5, 4, 2, 4, 3, 5, 2, 5, 7, 4, 7, 5, 5, 3, 5, 4, 6, 6, 8, 5
(列表;图表;参考;听;历史;文本;内部格式)
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抵消
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0,1
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参考文献
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C.Caldwell和H.Dubner,“初等、阶乘和多因子素数”,《数学》。《光谱》,26:1(1993/4)1-7。
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链接
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例子
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示例1+7=2^3所以a(1)=3。
a(3)=a(4)=a(5)=a(6)=1,因为3+1 = 13, 4!+7 = 31, 5!+1 = 127, 6!+7=727,这些都是质数。a(11)=a(15)=a+7 = 39916807 = 7 * 5702401, 15!+7 = 1307674368007 = 7 * 186810624001, 16!+7 = 20922789888007 = 7 * 2988969984001, 25!+7 = 15511210043330985984000007 = 7 * 2215887149047283712000001, 35!+7 = 10333147966386144929666651337523200000007 = 7 *
1476163995198020704238093048217600000001和59+7=138683118545689835737379197203894063459028767726874325408212949401600000000007=7*19811874077955699081970574245769915192271839538955347505831635628800000001都是半素数。
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交叉参考
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关键字
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容易的,非n
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作者
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扩展
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状态
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经核准的
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