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A072937
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Least k such that prime(n) appears in factorization of k! + 1.
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1
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2, 4, 3, 5, 12, 16, 9, 14, 18, 30, 36, 40, 21, 23, 52, 15, 8, 18, 7, 72, 23, 13, 88, 96, 100, 6, 106, 86, 112, 63, 65, 16, 16, 50, 150, 156, 81, 166, 172, 89, 180, 95, 102, 196, 99, 210, 222, 61, 228, 64, 210, 240, 97, 31, 131, 9, 93, 40, 280, 282, 45, 63, 220, 312, 91
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OFFSET
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2,1
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LINKS
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EXAMPLE
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12!+1 = 13^2*2834329 and 12 is the smallest integer k such that 13 = prime(6) appears in k!+1 factorization, hence a(6)=12
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PROG
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(PARI) a(n)=if(n<0, 0, s=1; while((s!+1)%prime(n)>0, s++); s)
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CROSSREFS
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Cf. A073944 (duplicate of this sequence, with an initial term a(1)=1).
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KEYWORD
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easy,nonn
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AUTHOR
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STATUS
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approved
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