A281190 Concatenation of the reversed digits of numbers from 1 to n, mod n.
0, 0, 0, 2, 0, 0, 5, 6, 0, 1, 6, 9, 3, 1, 6, 9, 5, 9, 1, 2, 18, 6, 12, 18, 2, 6, 18, 26, 7, 3, 20, 27, 6, 3, 28, 27, 7, 19, 12, 24, 4, 24, 12, 28, 9, 8, 42, 12, 22, 5, 3, 45, 41, 45, 50, 45, 45, 23, 16, 6, 6, 54, 27, 30, 61, 6, 37, 30, 21, 67, 47, 63, 52, 67, 57, 19, 28, 15, 58, 28, 72, 22, 56, 24, 83, 34, 3, 72, 72, 9, 85, 69, 57
Offset: 1
Examples
a(13) = A138957(13) mod 13 == 12345678901112131 mod 13 == 3.
Links
- Indranil Ghosh, Table of n, a(n) for n = 1..20008
Programs
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Mathematica
f[n_] := Mod[ Fold[#1*10^IntegerLength@#2 + FromDigits@ Reverse@ IntegerDigits@#2 &, 0, Range@ n], n]; Array[f, 105]
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PARI
a(n) = my(s = ""); for (k=1, n, sk = digits(k); forstep (j=#sk, 1, -1, s = concat(s, sk[j]))); eval(s) % n; \\ Michel Marcus, Jan 28 2017
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Python
def A281190(n): s="" for i in range(1,n+1): s+=str(i)[::-1] return int(s)%n # Indranil Ghosh, Jan 28 2017
Formula
a(n) = A138957(n) mod n.
Comments