1,1
Prime indices of palindromic triangular numbers.
P. De Geest, Subsets of palindromic triangulars
Cf. A008510, A050722.
Sequence in context: A065378 A161721 A079853 * A058114 A042337 A061482
Adjacent sequences: A050718 A050719 A050720 * A050722 A050723 A050724
nonn,base,hard
Patrick De Geest (pdg(AT)worldofnumbers.com), Sep 15 1999.