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A023720
Numbers with exactly 3 3's in base 4 expansion.
1
63, 127, 191, 207, 223, 239, 243, 247, 251, 252, 253, 254, 319, 383, 447, 463, 479, 495, 499, 503, 507, 508, 509, 510, 575, 639, 703, 719, 735, 751, 755, 759, 763, 764, 765, 766, 783, 799, 815, 819, 823, 827, 828, 829, 830
OFFSET
1,1
LINKS
MATHEMATICA
Select[ Range[ 864 ], (Count[ IntegerDigits[ #, 4 ], 3 ]==3)& ]
CROSSREFS
Sequence in context: A256813 A324488 A080947 * A031468 A045064 A043450
KEYWORD
nonn,base,easy
STATUS
approved