A273158 Number of concatenations nm consisting of n followed by a positive integer m (not a multiple of 10) that are divisible by m.

5, 6, 12, 8, 8, 14, 14, 9, 21, 9, 14, 17, 16, 17, 19, 11, 16, 25, 16, 11, 32, 17, 16, 20, 11, 18, 33, 20, 17, 21, 17, 12, 33, 18, 20, 29, 17, 18, 35, 12, 17, 37, 17, 20, 31, 18, 17, 23, 26, 12

Offset

1,1

Links

Reiner Moewald, Table of n, a(n) for n = 1..98

Formula

m <= n * 5^a(2 + floor(log_10(n))) with a(n) from A066343.

Example

a(1)=5 since 1|11, 2|12, 5|15, 25|125, 125|1125.

Prog

(Python)
# for N < 100
import math
for N in range (1, 100):
   ANZ = 0
   for M in range(1, 195312500):
      Z = int(str(int(N)) + str(int(M)))
      if ((Z % M == 0) and (M % 10 > 0)):
         ANZ = ANZ + 1
   print(N, ANZ)

Crossrefs

Cf. A066343.

Sequence in context: A328544 A041939 A177714 * A099641 A207189 A285404

Adjacent sequences: A273155 A273156 A273157 * A273159 A273160 A273161

Keyword

nonn,base

Author

Reiner Moewald, May 16 2016

Status

approved