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Numbers k such that reverse(gpf(k)) = gpf(k+1), where gpf(n) = A006530(n); a(1)=1.
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%I #16 Jun 02 2024 14:39:52

%S 1,73,155,425,650,1053,1243,1364,1632,1859,1988,2133,2774,4046,4991,

%T 5328,5475,5529,6292,8029,8176,10730,12495,13431,17459,17576,17879,

%U 18980,20329,20855,20944,22815,24024,25122,26936,28518,29319,29784

%N Numbers k such that reverse(gpf(k)) = gpf(k+1), where gpf(n) = A006530(n); a(1)=1.

%e 29319 is a term because 29319 = 3*29*337 and 29320 = 2*2*2*5*733.

%t p =(FactorInteger@#)[[-1, 1]] & /@ Range@(10^6);Prepend[Flatten@Position[Transpose[{Most@p,IntegerReverse@Rest@p}],{a_,a_}],1] (* _Hans Rudolf Widmer_, Jun 02 2024 *)

%o (PARI) gpf(k) = vecmax(factor(k)[,1]); \\ A006530

%o isok(k) = (k==1) || fromdigits(Vecrev(digits(gpf(k)))) == gpf(k+1); \\ _Michel Marcus_, Jun 02 2024

%Y Cf. A004086, A006530.

%K base,nonn

%O 1,2

%A _Jason Earls_, Jun 08 2002