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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 (list; graph; refs; listen; history; text; internal format)
OFFSET

3,1

COMMENTS

Is it true that there is no term for n = 56? - T. D. Noe, Oct 03 2011

LINKS

Table of n, a(n) for n=3..46.

T. Trotter, Polygonal numbers

EXAMPLE

15151 is the smallest palindromic triangular number.

121 is the smallest palindromic 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

Adjacent sequences:  A196492 A196493 A196494 * A196496 A196497 A196498

KEYWORD

nonn,base

AUTHOR

Kausthub Gudipati, Oct 03 2011

STATUS

approved

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Last modified March 25 10:23 EDT 2019. Contains 321470 sequences. (Running on oeis4.)