A066190 Numbers k such that the sum of the even aliquot parts of k divides k.
4, 6, 10, 12, 14, 22, 26, 34, 38, 46, 56, 58, 62, 74, 82, 86, 94, 106, 118, 122, 134, 142, 146, 158, 166, 178, 194, 202, 206, 214, 218, 226, 254, 262, 274, 278, 298, 302, 314, 326, 334, 346, 358, 362, 382, 386, 394, 398, 422, 446, 454, 458, 466, 478, 482, 502
Offset: 1
Keywords
Links
- Harry J. Smith, Table of n, a(n) for n = 1..1000
Programs
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Mathematica
Do[ d = Drop[ Divisors[ n ], -1 ]; l = Length[ d ]; ev = 0; k = 2; While[ k <= l, If[ EvenQ[ d[ [ k ] ] ], ev = ev + d[ [ k ] ] ]; k++ ]; If[ IntegerQ[ n/ev ], Print[ n ] ], {n, 2, 10^3, 2} ] Select[Range[550],Divisible[#,Total[Select[Most[Divisors[#]],EvenQ]]]&]//Quiet (* Harvey P. Dale, Mar 11 2011 *)
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PARI
{ n=0; for (m=1, 10^9, d=divisors(m); s=0; for (i=2, numdiv(m) - 1, if (d[i]%2 == 0, s += d[i])); if (s > 0 && m%s == 0, write("b066190.txt", n++, " ", m); if (n==1000, return)) ) } \\ Harry J. Smith, Feb 05 2010
Formula
a(n) = 2*A053813(n). - Amiram Eldar, Jul 07 2022
Extensions
a(56) from Harry J. Smith, Feb 05 2010