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A151993 Number of Honaker primes (A033548) less than 10^n. 0
0, 0, 3, 63, 410, 2949, 21622, 175504, 1478015, 12330087, 107585476, 937135794 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,3
COMMENTS
G. L. Honaker, Jr. computed the first six terms. Are there an infinite number of Honaker primes?
LINKS
EXAMPLE
a(3) = 3 because 131, 263, and 457 are the only Honaker primes less than 10^3.
MATHEMATICA
nn=6; cnt=0; power10=10; Reap[Do[p=Prime[k]; If[p>power10, Sow[cnt]; power10=10*power10]; If[Total[IntegerDigits[k]] == Total[IntegerDigits[p]], cnt++ ], {k, PrimePi[10^nn]+1}]][[2, 1]]
CROSSREFS
Cf. A006880 (primes < 10^n).
Sequence in context: A123754 A048354 A046181 * A120053 A139293 A370827
KEYWORD
hard,nonn,base
AUTHOR
T. D. Noe, Sep 14 2009
STATUS
approved

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Last modified July 19 16:24 EDT 2024. Contains 374410 sequences. (Running on oeis4.)