A095222 (Concatenation of T(n)+1..T(n+1)) mod (concatenation of T(n-1)+1..T(n)), where T(k) is the k-th triangular number, A000217(k).

0, 19, 22, 52785, 459136846, 77032955851, 17865523926168, 1689623507805373, 118763391490664275, 34129170492806856511, 3616977859402101826424, 614427099275584124069065, 34445463838393113230619233, 2480185781714663029796564541499860

Offset

1,2

Links

Harvey P. Dale, Table of n, a(n) for n = 1..200

Formula

a(n) = A053067(n+1) mod A053067(n). - Hagen von Eitzen, Jun 17 2009

Example

a(3) = 78910 mod 456 = 22.
From Jon E. Schoenfield, Feb 23 2021: (Start)
.
      concatenation of  concatenation of
   n   T(n-1)+1..T(n)    T(n)+1..T(n+1)    a(n)
  --  ----------------  ----------------  -----
   1                 1                23      0
   2                23               456     19
   3               456             78910     22
   4             78910        1112131415  52785
(End)

Mathematica

ccat[a_, b_]:=FromDigits[Flatten[IntegerDigits/@Range[a, b]]]; modc[n_]: = Module[{w=(n(n-1))/2+1, x=(n(n+1))/2, y, z}, y=x+1; z=2x-w+2; Mod[ccat[y, z], ccat[w, x]]]; Array[modc, 20] (* Harvey P. Dale, Nov 27 2012 *)

Crossrefs

Cf. A000217, A053067.

Sequence in context: A050955 A303299 A072305 * A343740 A317254 A226687

Adjacent sequences: A095219 A095220 A095221 * A095223 A095224 A095225

Keyword

base,nonn,less

Author

Amarnath Murthy, Jun 10 2004

Extensions

More terms from Hagen von Eitzen, Jun 17 2009

a(14) from Harvey P. Dale, Nov 27 2012

Status

approved