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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).
1
0, 19, 22, 52785, 459136846, 77032955851, 17865523926168, 1689623507805373, 118763391490664275, 34129170492806856511, 3616977859402101826424, 614427099275584124069065, 34445463838393113230619233, 2480185781714663029796564541499860
OFFSET
1,2
LINKS
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
Sequence in context: A050955 A303299 A072305 * A343740 A317254 A226687
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