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A164944
Decimal value of the concatenation of first n even numbers in binary.
0
2, 20, 166, 2664, 42634, 682156, 10914510, 349264336, 11176458770, 357646680660, 11444693781142, 366230200996568, 11719366431890202, 375019725820486492, 12000631226255567774, 768040398480356337568, 49154585502742805604386
OFFSET
1,1
EXAMPLE
a(3)=166 because the first 3 even numbers in binary are 10 100 110, and the concatenation 10100110 in base 10 = 166. a(4)=2664 because the first 4 even numbers in binary are 10 100 110 1000, and the concatenation 101001101000 in base 10 = 2664.
PROG
(Python)
def a(n):return int("".join(bin(2*(i+1))[2:] for i in range(n)), 2)
print([a(n) for n in range(1, 19)]) # Michael S. Branicky, Feb 20 2021
CROSSREFS
Sequence in context: A270444 A093130 A043029 * A144485 A115489 A367939
KEYWORD
base,easy,nonn
AUTHOR
Gil Broussard, Sep 01 2009
STATUS
approved