A076166 Primes p such that sum of cubes of even digits of p equals sum of cubes of odd digits of p.

16447, 41467, 41647, 44617, 46147, 46471, 76441, 114451, 144511, 146407, 404167, 404671, 414607, 415141, 416407, 440761, 441607, 451411, 460147, 460417, 461407, 470461, 476041, 476401, 541141, 610447, 640741, 644107, 644701, 647401, 704461, 740461, 746041, 764041

Offset: 1

Author

Zak Seidov, Nov 01 2002

Keywords

• nonn
• base
• less

Comments

Minimal number of digits in p is 5. n such that sum of even digits equals sum of odd digits in A036301.

To find terms of this sequence, one could look at zerofree positive integers having the criterion on sum of cubes of digits. Then permute the digits to see which are prime. Using those digits with 0 and permuting then only needs the check on primality. - David A. Corneth, Dec 11 2018

Examples

			16447 is OK because 1^3 + 7^3 = 6^3 + 4^3 + 4^3.
14467 has digits in nondecreasing order (is zerofree). Of the 60 permutations, 16447, 41467, 41647, 44617, 46147, 46471, 76441 are prime. - _David A. Corneth_, Dec 11 2018
		

Links

• Marius A. Burtea, Table of n, a(n) for n = 1..5869

Crossrefs

Cf. A009994, A036301.

Subsequence of A076165.

Programs

Mathematica

oeQ[n_]:=Module[{idn = IntegerDigits[n]}, Total[Select[idn, OddQ]^3] == Total[ Select[idn, EvenQ]^3]]; Select[Range[100000], PrimeQ[#] && oeQ[#] &] (* Amiram Eldar, Dec 10 2018 after Harvey P. Dale at A076165 *)

PARI

isok(p) = isprime(p) && (d=digits(p)) && (sum(i=1, #d, d[i]^3*if(d[i]%2, 1, -1))==0); \\ Michel Marcus, Dec 13 2018