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A046348 Composite palindromes divisible by the sum of their prime factors (counted with multiplicity). 3
4, 646, 2772, 5445, 8778, 30303, 48384, 50505, 54145, 63336, 77077, 117711, 219912, 234432, 239932, 255552, 272272, 294492, 535535, 585585, 636636, 717717, 825528, 888888, 951159, 999999, 1103011, 1112111, 1345431, 2248422, 2267622 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

David A. Corneth, Table of n, a(n) for n = 1..4180 (Terms <= 10^15. First 1000 terms from R. J. Mathar and Giovanni Resta)

David A. Corneth, PARI prog

EXAMPLE

a(2)=646 :  2*17*19 -> 2 + 17 + 19 = 38 and 646 / 38 = 17.

MATHEMATICA

t={}; Do[If[!PrimeQ[n]&&Reverse[x=IntegerDigits[n]]==x&&IntegerQ[n/Total[Times@@@FactorInteger[n]]], AppendTo[t, n]], {n, 4, 2.5*10^6}]; t (* Jayanta Basu, Jun 04 2013 *)

cpdQ[n_]:=CompositeQ[n]&&PalindromeQ[n]&&Divisible[n, Total[ Flatten[ Table[ #[[1]], #[[2]]]&/@FactorInteger[n]]]]; Select[Range[23*10^5], cpdQ] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, May 01 2018 *)

PROG

(PARI) See PARI link.

CROSSREFS

Cf. A002113, A001414, A046346, A046347.

Sequence in context: A169619 A091288 A067171 * A183150 A202368 A114765

Adjacent sequences:  A046345 A046346 A046347 * A046349 A046350 A046351

KEYWORD

nonn,base

AUTHOR

Patrick De Geest, Jun 15 1998

STATUS

approved

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Last modified August 14 12:06 EDT 2018. Contains 313751 sequences. (Running on oeis4.)