cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A083449 a(n) = A019566(n)/9, where A019566(n) = concat(n,...,1) - concat(1,...,n).

Original entry on oeis.org

0, 1, 22, 343, 4664, 58985, 713306, 8367627, 96021948, -150891621, -13731137410, -260644605199, 86159119727012, 19839246664059223, 3106259112208391434, 422859356777752723645, 53509280234443297055856, 6473262479112108841388067, 759559693477989774385720278
Offset: 1

Views

Author

Amarnath Murthy and Meenakshi Srikanth (menakan_s(AT)yahoo.com), May 01 2003

Keywords

Comments

Are there any palindromes > 58985?
This sequence also gives the number of occurrences of any digit d > n (thus n < 9) in the list of all numbers from 1 to concatenation(1,...,n) = A007908(n) = A014824(n) = sum_{i=1..n} i*10^(n-i). See A277849, A061217, A277830 etc. - M. F. Hasler, Nov 01 2016, edited Nov 07 2020

Crossrefs

Cf. A061217.

Programs

  • Maple
    a:= n-> (parse(cat((n+1-i)$i=1..n))-parse(cat($1..n)))/9:
    seq(a(n), n=1..20);  # Alois P. Heinz, Nov 09 2020
  • Mathematica
    Array[(FromDigits@ Apply[Join, Reverse@ #] - FromDigits@ Apply[Join, #])/9 &@ Map[IntegerDigits, Range[#]] &, 19] (* Michael De Vlieger, Nov 12 2020 *)
  • PARI
    apply( {A083449(n)=A019566(n)\9}, [1..20]) \\ - M. F. Hasler, Nov 07 2020

Formula

For n < 10, a(n) = ceiling((9*n-11)*(10^n+1)/729). - M. F. Hasler, Nov 07 2020

Extensions

More terms from David Wasserman, Nov 09 2004