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A251605
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Numbers k = concat(s,t) such that k = antisigma(s) + antisigma(t), where antisigma(x) = A024816(x).
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1
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OFFSET
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1,1
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LINKS
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EXAMPLE
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226 = concat(22,6); 22*23/2 - sigma(22) = 253 - 36 = 217; 6*7/2 - sigma(6) = 21 - 12 = 9. Finally 217 + 9 = 226.
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MAPLE
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with(numtheory): P:=proc(q) local s, t, k; global n; for n from 1 to q do for k from 1 to ilog10(n) do s:=n mod 10^k; t:=trunc(n/10^k); if s>0 then if s*(s+1)/2-sigma(s)+t*(t+1)/2-sigma(t)=n
then print(n); break; fi; fi; od; od; end: P(10^7);
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CROSSREFS
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KEYWORD
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nonn,base,more
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AUTHOR
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EXTENSIONS
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Incorrect term 240 removed by and a(6)-a(7) from Jinyuan Wang, Feb 16 2021
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STATUS
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approved
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