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A196495
Smallest multidigit palindromic centered n-gonal number.
0
15151, 181, 141, 919, 22, 121, 55, 11, 111, 121, 131, 141, 151, 161, 171, 55, 191, 121, 22, 189949981, 484, 505, 151, 11311, 757, 16661, 88, 181, 72727, 33, 1111111, 10201, 10501, 757, 2636362, 17671, 51715, 121, 616, 36163, 44, 1856581, 676, 12256565221
OFFSET
3,1
COMMENTS
Is it true that there is no term for n = 56? - T. D. Noe, Oct 03 2011
No, the smallest multidigit palindromic centered 56-gonal number is 14075098988989057041 with base 709000780. - Patrick De Geest, Apr 25 2021
EXAMPLE
15151 is the smallest palindromic centered triangular number.
121 is the smallest palindromic centered 40-gonal number.
MATHEMATICA
palin[n_] := Module[{d = IntegerDigits[n]}, d == Reverse[d]]; Table[n = 1; While[num = n*k*(n-1)/2 + 1; num < 10 || ! palin[num], n++]; num, {k, 3, 50}] (* T. D. Noe, Oct 03 2011 *)
CROSSREFS
Sequence in context: A004955 A004975 A157436 * A031623 A105924 A259395
KEYWORD
nonn,base
AUTHOR
Kausthub Gudipati, Oct 03 2011
STATUS
approved