This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A333951 #10 Apr 12 2020 09:51:03 %S A333951 56924,82004,84524,109395,158235,241604,261260,266475,285075,361844, %T A333951 442035,445004,469755,611324,666315,694484,712844,922635,968715, %U A333951 971684,1102724,1172115,1190475,1199835,1239524,1304324,1338435,1430715,1442924,1486275,1523115,1550835 %N A333951 Numbers k such that both k and k+1 are recursive abundant numbers (A333928). %H A333951 Amiram Eldar, <a href="/A333951/b333951.txt">Table of n, a(n) for n = 1..10000</a> %e A333951 56924 is a term since A333926(56924) = 120960 > 2 * 56924, and A333926(56925) = 116064 > 2 * 56925. %t A333951 recDivQ[n_, 1] = True; recDivQ[n_, d_] := recDivQ[n, d] = Divisible[n, d] && AllTrue[FactorInteger[d], recDivQ[IntegerExponent[n, First[#]], Last[#]] &]; recDivs[n_] := Select[Divisors[n], recDivQ[n, #] &]; f[p_, e_] := 1 + Total[p^recDivs[e]]; recDivSum[1] = 1; recDivSum[n_] := Times @@ (f @@@ FactorInteger[n]); recAbQ[n_] := recDivSum[n] > 2*n; Select[Range[2*10^5], recAbQ[#] && recAbQ[# + 1] &] %Y A333951 Subsequence of A333928. %Y A333951 Cf. A333926, A333950. %Y A333951 Analogous sequences: A096399, A283418 (primitive), A318167 (bi-unitary), A327635 (infinitary), A327942 (nonunitary), A331412 (unitary). %K A333951 nonn %O A333951 1,1 %A A333951 _Amiram Eldar_, Apr 11 2020