A064919 a(n) = Min { k | A064916(k) = n }.
2, 3, 6, 5, 10, 7, 14, 16, 18, 11, 22, 13, 26, 28, 30, 17, 34, 19, 38, 40, 42, 23, 46, 48, 50, 52, 54, 29, 58, 31, 62, 64, 66, 68, 70, 37, 74, 76, 78, 41, 82, 43, 86, 88, 90, 47, 94, 96, 98, 100, 102, 53, 106, 108, 110, 112, 114, 59, 118, 61, 122, 124, 126, 128, 130, 67
Offset: 2
Keywords
Links
- Harry J. Smith, Table of n, a(n) for n = 2..1000
Programs
-
PARI
lpf(n)= { local(f); f=factor(n); return(f[1, 1]) } { for (n=2, 1000, k=1; until (m==n, k++; L=lpf(k); m=k / L + L - 1); write("b064919.txt", n, " ", k) ) } \\ Harry J. Smith, Sep 29 2009
Formula
For n > 2: a(n) = if n is prime then n else 2*n - 2.
Comments