A151993 Number of Honaker primes (A033548) less than 10^n.

0, 0, 3, 63, 410, 2949, 21622, 175504, 1478015, 12330087, 107585476, 937135794

Offset

1,3

Comments

G. L. Honaker, Jr. computed the first six terms. Are there an infinite number of Honaker primes?

Links

Table of n, a(n) for n=1..12.

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

Adjacent sequences: A151990 A151991 A151992 * A151994 A151995 A151996

Keyword

hard,nonn,base

Author

T. D. Noe, Sep 14 2009

Status

approved