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A033548 Honaker primes: primes P(k) such that sum of digits of P(k) equals sum of digits of k. 28
131, 263, 457, 1039, 1049, 1091, 1301, 1361, 1433, 1571, 1913, 1933, 2141, 2221, 2273, 2441, 2591, 2663, 2707, 2719, 2729, 2803, 3067, 3137, 3229, 3433, 3559, 3631, 4091, 4153, 4357, 4397, 4703, 4723, 4903, 5009, 5507, 5701, 5711, 5741, 5801, 5843 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

A090431(A049084(a(n))) = 0.

REFERENCES

Proposed by G. L. Honaker, Jr.

LINKS

T. D. Noe and Charles R Greathouse IV, Table of n, a(n) for n = 1..10000 (first 1000 terms from Noe)

EXAMPLE

131 is the 32nd prime and sum of digits of both is 5.

MAPLE

P:=proc(n) local a; a:=ithprime(n);

if convert(convert(n, base, 10), `+`)=convert(convert(a, base, 10), `+`) then a; fi; end:

seq(P(i), i=1..10^3); # Paolo P. Lava, Jun 29 2017

MATHEMATICA

Prime[ Select[ Range[ 2000 ], Apply[ Plus, IntegerDigits[ # ] ] == Apply[ Plus, IntegerDigits[ Prime[ # ] ] ] & ] ] (* Santi Spadaro, Oct 14 2001 *)

Select[ Prime@ Range@ 5927, Plus @@ IntegerDigits@ # == Plus @@ IntegerDigits@ PrimePi@ # &]  (* Robert G. Wilson v, Jun 07 2009 *)

nn=800; Transpose[Select[Thread[{Prime[Range[nn]], Range[nn]}], Total[IntegerDigits[First[#]]]== Total[ IntegerDigits[ Last[#]]]&]][[1]] (* Harvey P. Dale, Jun 13 2011 *)

PROG

(Haskell)

a033548 n = a033548_list !! (n-1)

a033548_list = filter ((== 0) . a090431 . a049084) a000040_list

-- Reinhard Zumkeller, Mar 16 2014

(PARI) is(n)=isprime(n) && sumdigits(n)==sumdigits(primepi(n)) \\ Charles R Greathouse IV, Jun 18 2015

(Python)

from sympy.ntheory.factor_ import digits

from sympy import primepi, primerange

print [n for n in primerange(1, 5901) if (sum(digits(n)[1:])==sum(digits(primepi(n))[1:]))] # Indranil Ghosh, Jun 27 2017, after Charles R Greathouse IV

CROSSREFS

Cf. A033549, A049084, A072439, A090431.

Sequence in context: A142616 A207527 A132249 * A117477 A089316 A242846

Adjacent sequences:  A033545 A033546 A033547 * A033549 A033550 A033551

KEYWORD

nonn,base,nice

AUTHOR

Calculated by Jud McCranie

EXTENSIONS

More terms from Robert G. Wilson v, Jun 07 2009

STATUS

approved

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Last modified June 17 07:00 EDT 2019. Contains 324183 sequences. (Running on oeis4.)