A196677 Numbers n such that sum of the divisors of n equals the sum of the reversals of the divisors of n. Numbers with all palindrome divisors are not in the sequence.
30, 42, 330, 462, 681, 772, 824, 890, 989, 2180, 3030, 4242, 4542, 4722, 8074, 9775, 17331, 23980, 33330, 35823, 36213, 43263, 46662, 47324, 55805, 62121, 62421, 65301, 65451, 66441, 66741, 68181, 68331, 68631, 68781, 69171, 71215, 71452, 73565, 74391, 74417, 74572, 74972
Offset: 1
Examples
Divisors of 989 are 1, 23, 43, 989 and 1+23+43+989=1+32+34+989=1056. Divisors of 8074 are 1, 2, 11, 22, 367, 734, 4037, 8074 and 1+2+11+22+367+734+4037+8074=1+2+11+22+763+437+7304+4708=13248.
Links
- Giovanni Resta, Table of n, a(n) for n = 1..10000 (terms 1..57 from R. J. Mathar, 58..1000 from Amiram Eldar)
Programs
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Magma
f:=func
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Maple
Rev:=proc(n) local a,i,k; i:=convert(n,base,10); a:=0; for k from 1 to nops(i) do a:=a*10+i[k]; od; a; end: P:=proc(j) local h,m,n,ok,p,r,t; for m from 1 to j do p:=divisors(m); t:=0; ok:=0; for r from 1 to nops(p) do t:=t+Rev(p[r]); if p[r]<>Rev(p[r]) then ok:=1; fi; od; if ok=1 and sigma(m)=t then print(m); fi; od; end: P(100000); # alternative isA196677 := proc(n) isA080716(n) and not isA062687(n) ; end proc: n := 1; for i from 1 do if isA196677(i) then printf("%d %d\n",n,i) ; n := n+1 ; end if; end do: # R. J. Mathar, Sep 09 2015
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