login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A083973
Smallest palindromic prime containing exactly n 2's.
10
2, 12421, 72227, 1221221, 3222223, 122232221, 322222223, 12222122221, 1202222222021, 1222227222221, 9222222222229, 122222232222221, 32222322222322223, 72222222422222227, 1202222222222222021, 1222222226222222221, 125222222222222222521, 722222222202222222227
OFFSET
1,1
LINKS
MATHEMATICA
Table[d = 2; i = 1;
While[ x = IntegerDigits[Prime[i]];
x != Reverse[x] || Count[x, d] != n , i++];
FromDigits[x], {n, 1, 6}] (* Robert Price, Mar 25 2019 *)
KEYWORD
base,nonn
AUTHOR
Amarnath Murthy and Meenakshi Srikanth (menakan_s(AT)yahoo.com), May 21 2003
EXTENSIONS
Corrected and extended by Giovanni Resta, Feb 08 2006
STATUS
approved