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.

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

Author

Stefano Spezia, Sep 12 2021

Keywords

• nonn
• base

Comments

Intersection of A324297 and A347253.

Examples

			96 = 4*24 = 6*16, 216 = 4*54 = 6*36, 256 = 4*64 = 16*16, 336 = 4*84 = 6*56, ...
		

Crossrefs

Cf. A017341 (supersequence), A324297, A347253, A347748.

Programs

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<#
				

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

Formula

Lim_{n->infinity} a(n)/a(n-1) = 1.