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A347746
Positive integers that are equal both to the product of two integers ending with 4 and to that of two integers ending with 6.
1
96, 216, 256, 336, 416, 456, 576, 696, 736, 756, 816, 896, 936, 1056, 1176, 1216, 1296, 1376, 1416, 1456, 1536, 1596, 1656, 1696, 1776, 1836, 1856, 1896, 1976, 2016, 2136, 2176, 2256, 2336, 2376, 2436, 2496, 2576, 2616, 2656, 2736, 2816, 2856, 2916, 2976, 3016
OFFSET
1,1
COMMENTS
Intersection of A324297 and A347253.
FORMULA
Lim_{n->infinity} a(n)/a(n-1) = 1.
EXAMPLE
96 = 4*24 = 6*16, 216 = 4*54 = 6*36, 256 = 4*64 = 16*16, 336 = 4*84 = 6*56, ...
MATHEMATICA
max=3050; Select[Intersection[Union@Flatten@Table[a*b, {a, 4, Floor[max/4], 10}, {b, a, Floor[max/a], 10}], Union@Flatten@Table[a*b, {a, 6, Floor[max/6], 10}, {b, a, Floor[max/a], 10}]], 0<#<max&]
PROG
(Python)
def aupto(lim): return sorted(set(a*b for a in range(4, lim//4+1, 10) for b in range(a, lim//a+1, 10)) & set(a*b for a in range(6, lim//6+1, 10) for b in range(a, lim//a+1, 10)))
print(aupto(3017)) # Michael S. Branicky, Sep 12 2021
CROSSREFS
Cf. A017341 (supersequence), A324297, A347253, A347748.
Sequence in context: A044428 A044809 A115437 * A241930 A270435 A110231
KEYWORD
nonn,base
AUTHOR
Stefano Spezia, Sep 12 2021
STATUS
approved