OFFSET
1,1
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..5000
MATHEMATICA
Select[Range[2, 8000], DivisorSigma[0, # - 1] == 12 && DivisorSigma[0, # + 1] == 12 &] (* G. C. Greubel, Dec 29 2017 *)
SequencePosition[DivisorSigma[0, Range[5000]], {12, _, 12}][[All, 1]]+1 (* Harvey P. Dale, Jul 21 2021 *)
PROG
(PARI) for(n=2, 10^4, if( numdiv(n-1)==12 && numdiv(n+1)==12, print1(n, ", "))); /* Joerg Arndt, May 13 2011 */
CROSSREFS
KEYWORD
nonn
AUTHOR
Juri-Stepan Gerasimov, May 09 2011
EXTENSIONS
Terms corrected by R. J. Mathar, May 25 2011
STATUS
approved