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A162222
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Base 5 perfect digital invariants (written in base 10): numbers equal to the sum of the k-th powers of their base-5 digits, for some k.
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11
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0, 1, 2, 3, 4, 13, 18, 28, 118, 257, 289, 308, 353, 419, 4890, 4891, 9113, 16387, 66562, 322217, 1874374, 172449032, 268533762, 338749352, 2204944815, 2204944816, 2415951874, 3250054360, 3250054361, 3264337734, 4424304070, 4424304071
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OFFSET
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1,3
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COMMENTS
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Whenever a(n) is a multiple of 5, then a(n+1) = a(n) + 1 is also a base 5 perfect digital invariant, with the same exponent k. - M. F. Hasler, Nov 21 2019
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LINKS
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PROG
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(PARI) select( {is_A162222(n, b=5)=n<b||forstep(k=logint(n, max(vecmax(b=digits(n, b)), 2)), 2, -1, my(t=vecsum([d^k|d<-b])); t>n||return(t==n))}, [0..10^5]) \\ M. F. Hasler, Nov 21 2019
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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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STATUS
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approved
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