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A232893 Numbers whose sum of square divisors is a palindrome in base 10 having at least two digits. 1
15376, 30752, 46128, 76880, 92256, 107632, 153760, 169136, 199888, 215264, 230640, 261392, 292144, 322896, 338272, 353648, 399776, 445904, 461280, 476656, 507408, 522784, 538160, 568912, 584288, 599664, 630416, 645792, 661168, 707296, 722672, 784176, 814928, 845680, 876432 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..35.

EXAMPLE

Sum of square divisor of 15376, 15376+3844+961+16+4+1=20202, a palindrome with five digits.

MATHEMATICA

ssdpQ[n_]:=Module[{s=Total[Select[Divisors[n], IntegerQ[Sqrt[#]]&]]}, IntegerLength[ s]>1 &&s==IntegerReverse[s]]; Select[Range[ 900000], ssdpQ] (* The program uses the IntegerReverse function from Mathematica version 10 *) (* Harvey P. Dale, Jan 31 2016 *)

PROG

(PARI)

reverse(n)=concat(Vecrev(Str(n)))

palind(n)=(Str(n)==reverse(n)&&n>10)

{for(n=1, 10^6, k=sumdiv(n, d, d*issquare(d)); if(palind(k), print(n)))}

CROSSREFS

Cf. A232892.

Sequence in context: A232382 A175751 A054834 * A054835 A182255 A054836

Adjacent sequences:  A232890 A232891 A232892 * A232894 A232895 A232896

KEYWORD

nonn,base

AUTHOR

Antonio Roldán, Dec 02 2013

STATUS

approved

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Last modified January 21 13:38 EST 2018. Contains 297994 sequences.