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A073844
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a(1) = 1, a(n) = largest prime divisor of A057137(n).
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1
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1, 3, 41, 617, 823, 643, 9721, 14593, 3803, 3803, 14405693, 10288065751, 116216501, 12079920647, 7552031, 435503, 1763668414462081, 106377431, 27961, 27961, 205126079, 84225392753, 7347135846537257, 437274720469, 12792129877, 244251294564157
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OFFSET
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1,2
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LINKS
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FORMULA
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PROG
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(PARI) a(n) = if(n==1, 1, vecmax(factor(sum(i=1, n, i%10*10^(n-i)))[, 1])); \\ Daniel Suteu, May 25 2022
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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