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A112718
Numbers n such that pi(n)=1^d_1+2^d_2+...+k^d_k where d_1 d_2 ... d_k is the decimal expansion of n.
4
2, 12, 23, 113, 151, 5924, 14254, 106545, 1915765, 2798136, 31749441, 35282317, 35389065, 35389165, 105227821, 141291863, 193789064, 326730783, 839512048, 882012907, 884676937, 2780026914, 2997751947, 8493184690, 8493955191
OFFSET
1,1
COMMENTS
The largest term is less than 10^12 because if m>12 then 1^9+2^9+...+n^9 < pi(10^(m-1)). There is no further term up to 41*10^7.
LINKS
Giovanni Resta, Table of n, a(n) for n = 1..33 (full sequence)
EXAMPLE
326730783 is in the sequence because pi(326730783)=1^3+2^2+3^6+
4^7+5^3+6^0+7^7+8^8+9^3.
MATHEMATICA
Do[d=IntegerDigits[n]; k=Length[d]; If[PrimePi[n]==Sum[j^d[[j]], {j, k}], Print[n]], {n, 410000000}]
CROSSREFS
KEYWORD
base,fini,full,nonn
AUTHOR
Farideh Firoozbakht, Sep 17 2005
EXTENSIONS
a(19)-a(25) from Donovan Johnson, Nov 09 2010
STATUS
approved