A073939 Least m such that A078142(m) gives the n-th prime, where A078142(n) is the sum of the differences of the distinct prime factors p of n and the next square larger than p.

2, 6, 11, 22, 53, 106, 83, 166, 173, 227, 293, 863, 443, 857, 853, 971, 1097, 2194, 1229, 1373, 2746, 2837, 2221, 2027, 2819, 3499, 4253, 3257, 3491, 3251, 4229, 4493, 5639, 6917, 6907, 7949, 6899, 7937, 7229, 7927, 11057, 10223, 9413, 10211, 9803

Offset

1,1

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Example

a(4)=22 because A078142(22)=7, the fourth prime and this is the first time 7 occurs.

Mathematica

s[n_] := Total[Ceiling[Sqrt[(p = FactorInteger[n][[;; , 1]])]]^2 - p]; max=45; seq=Table[0, {max}]; c = 0; n=1; While[c<max, s1=s[n]; If[PrimeQ[s1], i=PrimePi[s1]; If[i<=max && seq[[i]]==0, c++; seq[[i]] = n]]; n++]; seq (* Amiram Eldar, Dec 08 2019 *)

Crossrefs

Cf. A078142.

Sequence in context: A305101 A363936 A083322 * A085264 A005999 A102429

Adjacent sequences: A073936 A073937 A073938 * A073940 A073941 A073942

Keyword

nonn

Author

Jason Earls, Nov 20 2002

Status

approved