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A073919 Smallest prime p with bigomega(p-1)=n, where bigomega(m)=A001222(m) is the number of prime divisors of m (counted with multiplicity). 3
2, 3, 5, 13, 17, 73, 97, 193, 257, 769, 3457, 7681, 15361, 12289, 40961, 114689, 65537, 737281, 1376257, 786433, 5308417, 7340033, 14155777, 28311553, 104857601, 113246209, 167772161, 469762049, 2113929217, 1811939329 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

LINKS

David W. Wilson and Robert G. Wilson v, Table of n, a(n) for n = 0..351

EXAMPLE

a(2) = 5 = 2*2 + 1. a(5) = 73 = 2*2*2*3*3 + 1.

MATHEMATICA

ptns[n_, 0] := If[n==0, {{}}, {}]; ptns[n_, k_] := Module[{r}, If[n<k, Return[{}]]; ptns[n, k]=1+Union@@Table[PadRight[ #, k]&/@ptns[n-k, r], {r, 0, k}]]; a[n_] := Module[{i, l, v}, v=Infinity; For[i=n, True, i++, l=(Times@@Prime/@#&)/@ptns[i, n]; If[Min@@l>v, Return[v]]; minp=Min@@Select[l+1, ProvablePrimeQ]; If[minp<v, v=minp]]] (* First do <<NumberTheory`PrimeQ`. ptns[n, k] is list of partitions of n into exactly k parts *) Array[a, 30, 0]

With[{x=Table[{Prime[n], PrimeOmega[Prime[n]-1]}, {n, 104000000}]}, Transpose[ Table[ SelectFirst[x, #[[2]]==i&], {i, 0, 29}]][[1]]] (* Harvey P. Dale, Sep 28 2014 *)

CROSSREFS

Cf. A118883.

Sequence in context: A235624 A108562 A087523 * A162573 A087356 A281598

Adjacent sequences:  A073916 A073917 A073918 * A073920 A073921 A073922

KEYWORD

nonn

AUTHOR

Amarnath Murthy, Aug 18 2002

EXTENSIONS

Edited by Dean Hickerson, Nov 12 2002

STATUS

approved

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Last modified August 18 23:43 EDT 2017. Contains 290782 sequences.