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A077576
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a(1) = 1; for n > 1, a(n) = largest prime divisor of A062273(n).
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1
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1, 23, 19, 263, 823, 678901, 50993, 1279, 211, 150866941, 353594393, 757819, 9012345678901, 213408443, 11904282563, 435503, 21339439879, 7403356241, 13212859242013, 27961, 205126079, 5201061865265117273, 54843374833199, 1384232185401581113277, 12792129877
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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) f(n) = sum(i=1, n, ((n*(n-1)/2+i) % 10)*10^(n-i)); \\ A062273
a(n) = my(x=f(n)); if (x==1, 1, vecmax(factor(x)[, 1])); \\ Michel Marcus, May 26 2022
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CROSSREFS
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KEYWORD
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base,nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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