A217357
Semiprimes p such that next semiprime after p is p+30.
Original entry on oeis.org
32777, 88649, 91799, 113107, 165697, 273257, 310103, 322211, 326137, 460963, 466063, 468877, 480443, 483223, 506509, 509131, 553349, 564347, 565493, 587611, 616771, 623257, 624959, 625619, 739177, 766799, 777163, 826657, 832357, 834123, 845177, 860873, 916163
Offset: 1
32777 =A001358(8112) = 73*449, 32807 = A001358(8113) = 3*619,
88649 =A001358(20880) = 11*8059, 88679 = A001358(20881) = 71*1249.
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IsSemiprime:=func; [n: n in [4..1000000] | IsSemiprime(n) and IsSemiprime(n+30) and forall{n+i: i in [1..29] | not IsSemiprime(n+i)}]; // Bruno Berselli, Oct 01 2012
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Select[Partition[Select[Range[10^6],PrimeOmega[#]==2&],2,1],#[[2]]-#[[1]] == 30&][[All,1]] (* Harvey P. Dale, May 06 2022 *)
A282407
Semiprimes p such that next semiprime after p is p + 40.
Original entry on oeis.org
741841, 1633213, 1889467, 1946677, 2210557, 2440203, 2655427, 2660857, 2729091, 2749273, 2774911, 3077323, 3724909, 3977473, 4021507, 4030891, 4323301, 4372337, 4408581, 4421713, 4608574, 4640419, 4836223, 5640861, 5691531, 6148599, 6166101, 6429853, 6786523
Offset: 1
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is(p) = if(bigomega(p)==2 && bigomega(p+40)==2, for(i=p+1, p+39, if(bigomega(i)==2, return(0))); 1); \\ Jinyuan Wang, May 23 2021
A282424
Semiprimes p such that next semiprime after p is p + 50.
Original entry on oeis.org
1226777, 4732631, 5093729, 9210671, 12515461, 12917989, 16121409, 16183253, 16698881, 17263069, 19418903, 23003807, 24534161, 26519563, 26726659, 27625067, 29605299, 29772471, 32655031, 34027277, 34366179, 35340719, 37570683, 38117319, 38687461, 39038399, 39479381
Offset: 1
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lista(nn) = my(r); for(k=1, nn, if(bigomega(k)==2, if(k-r==50, print1(r, ", ")); r=k)); \\ Jinyuan Wang, May 23 2021
Showing 1-3 of 3 results.
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