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<a href="/index/Mo#MWP">Index entries for sequences related to Most Wanted Primes video</a>

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Bertrand Teguia Tabuguia, <a href="https://arxiv.org/abs/2201.07127">Explicit formulas for concatenations of arithmetic progressions</a>, arXiv:2201.07127 [math.CO], 2022.

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Serge Batalov: For me, O.K.

a(n) = ((n*9-1)*10^n+1)/9^2 for n< < 10,

a(n) = ((n*99-1)*10^(2*n-19)-89)/99^2*10^10+( + (8*10^10+1)/9^2 for 10<= <= n< < 100,

a(n) = ((n*999-1)*10^(3*n-299)-989)/999^2*10^191+ + c2 for 10^2<= <= n< < 10^3,

a(n) = ((n*9999-1)*10^(4*n-3999)-9989)/9999^2*10^2892+ + c3 for 10^3<= <= n< < 10^4,

a(n) = ((n*99999-1)*10^(5*n-49999)-99989)/99999^2*10^38893+ + c4 for 10^4<= <= n< < 10^5,

a(n) = ((n*999999-1)*10^(6*n-599999)-999989)/999999^2*10^488894+ + c5 for 10^5<= <= n< < 10^6,

c2 = (98*10^191+ + 879*10^10+ + 121)/99^2 = a(99),

c3 = (998*10^2701- - 989)/999^2*10^191+ + c2 = a(999),

c4 = (9998*10^36001- - 9989)/9999^2*10^2892+ + c3 = a(9999),

c5 = (99998*10^450001- - 99989)/99999^2*10^38893+ + c4 = a(99999).

a(n) = Sum_{k=1..n} k*10^(A058183(k)-) - (1+floor(loglog10(10k))). - _k)))). - _Alexander Goebel_, Mar 07 2020

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Jon E. Schoenfield: Okay?