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A157138
Even numbers k such that k and prime(k) have the same number of even digits.
0
10, 14, 18, 38, 48, 52, 54, 58, 60, 70, 76, 80, 82, 86, 92, 94, 96, 98, 112, 114, 124, 132, 136, 138, 140, 142, 144, 158, 170, 174, 180, 192, 194, 198, 234, 236, 252, 254, 258, 290, 306, 318, 320, 324, 326, 342, 348, 350, 352, 356, 364, 366, 368, 370, 374, 376
OFFSET
1,1
COMMENTS
Can this sequence be proved to be infinite?
EXAMPLE
10 is a term: prime(10)=29, and 10 and 29 each have 1 even digit.
14 is a term: prime(14)=43, and 14 and 43 each have 1 even digit.
18 is a term: prime(18)=61, and 18 and 61 each have 1 even digit.
124 is a term: prime(124)=683, and 124 and 683 each have 2 even digits.
CROSSREFS
KEYWORD
nonn,base,less
AUTHOR
EXTENSIONS
Roughly 50 percent of the entries corrected by R. J. Mathar, Feb 26 2009
Edited by Jon E. Schoenfield, Apr 18 2021
STATUS
approved