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A251605 Numbers k = concat(s,t) such that k = antisigma(s) + antisigma(t), where antisigma(x) = A024816(x). 1
226, 1046, 3881, 20206, 1970256, 57619059, 62109258 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..7.

EXAMPLE

226 = concat(22,6); 22*23/2 - sigma(22) = 253 - 36 = 217; 6*7/2 - sigma(6) = 21 - 12 = 9. Finally 217 + 9 = 226.

MAPLE

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);

CROSSREFS

Cf. A000203, A024816, A253824, A253825.

Sequence in context: A158229 A031708 A156814 * A233943 A234155 A251402

Adjacent sequences:  A251602 A251603 A251604 * A251606 A251607 A251608

KEYWORD

nonn,base,more

AUTHOR

Paolo P. Lava, Feb 02 2015

EXTENSIONS

Incorrect term 240 removed by and a(6)-a(7) from Jinyuan Wang, Feb 16 2021

STATUS

approved

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Last modified October 1 19:48 EDT 2022. Contains 357172 sequences. (Running on oeis4.)