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 A347749 Number of positive integers with n digits and final digit 6 that are equal to the product of two integers ending with the same digit. 2
 0, 4, 33, 352, 3597, 36781, 374071, 3790993, 38326689, 386782889 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS a(n) is the number of n-digit numbers in A347747. LINKS FORMULA a(n) < A052268(n). a(n) = A337856(n) + A347255(n) - A347748(n). Conjecture: lim_{n->infinity} a(n)/a(n-1) = 10. MATHEMATICA Table[{lo, hi}={10^(n-1), 10^n}; Length@Select[Union[Union@Flatten@Table[a*b, {a, 4, Floor[hi/4], 10}, {b, a, Floor[hi/a], 10}], Union@Flatten@Table[a*b, {a, 6, Floor[hi/6], 10}, {b, a, Floor[hi/a], 10}]], lo<#

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Last modified February 4 23:12 EST 2023. Contains 360082 sequences. (Running on oeis4.)