A192854 Places n where tau(n) + tau(n+2) = tau(2*n+2).
1, 3, 7, 13, 15, 21, 37, 43, 57, 91, 103, 123, 135, 147, 157, 171, 177, 230, 231, 235, 242, 255, 285, 331, 374, 381, 387, 411, 422, 451, 458, 483, 501, 507, 541, 547, 609, 620, 637, 667, 711, 717, 781, 805, 836, 860, 871, 877, 884, 901, 902, 907, 985, 1001, 1016, 1035, 1065, 1095, 1183, 1184, 1195
Offset: 1
Links
- G. C. Greubel, Table of n, a(n) for n = 1..10000
Programs
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Mathematica
Select[Range[1200], DivisorSigma[0, #] +DivisorSigma[0, # + 2] == DivisorSigma[0, 2*# +2] &] (* G. C. Greubel, Jan 06 2019 *)