OFFSET
1,2
LINKS
Giovanni Resta, Table of n, a(n) for n = 1..101 (terms < 10^12)
MATHEMATICA
Select[Range@100000, ({}!=StringPosition[ToString[ #(#+1)/2], ToString@# ]) &]
Select[Range[3*10^6], SequenceCount[IntegerDigits[(#(#+1))/2], IntegerDigits[ #]]>0&] (* The program uses the SequenceCount function from Mathematica version 10 *) (* Harvey P. Dale, Dec 26 2015 *)
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Giovanni Resta, May 10 2006
STATUS
approved