OFFSET
1,2
COMMENTS
1 is the smallest value of |A177961(m) - m|.
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
FORMULA
a(n) = (A002476(n-1) + 1)/2, n > 1.
MAPLE
1, op(map(t -> 3*t+1, select(t -> isprime(6*t+1), [$1..1000]))); # Robert Israel, Jul 31 2015
MATHEMATICA
Position[Table[If[m == 1, 2, Mean[{FactorInteger[2 m - 1][[1, 1]], FactorInteger[2 m + 1][[1, 1]]}]] - m, {m, 346}], n_ /; n == 1] // Flatten (* Michael De Vlieger, Aug 02 2015 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Vladimir Shevelev, May 16 2010
EXTENSIONS
More terms from R. J. Mathar, Oct 25 2010
STATUS
approved