cp's OEIS Frontend

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.

Showing 1-9 of 9 results.

A039949 Primes of the form 30n - 13.

Original entry on oeis.org

17, 47, 107, 137, 167, 197, 227, 257, 317, 347, 467, 557, 587, 617, 647, 677, 797, 827, 857, 887, 947, 977, 1097, 1187, 1217, 1277, 1307, 1367, 1427, 1487, 1607, 1637, 1667, 1697, 1787, 1847, 1877, 1907, 1997, 2027, 2087, 2207, 2237, 2267, 2297, 2357, 2417
Offset: 1

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Author

Keywords

Comments

This linear form produces the most primes for n between 1 and 1000 (411/1000).
Primes congruent to 17 (mod 30). - Omar E. Pol, Aug 15 2007
Primes ending in 7 with (SOD-1)/3 non-integer where SOD is sum of digits. - Ki Punches
Or primes p such that (p mod 3) = (p mod 5) and (p mod 2) <> (p mod 3), (p > 2). - Mikk Heidemaa, Jan 19 2016

References

  • C. Clawson, Mathematical Mysteries, Plenum Press, 1996, p. 173

Crossrefs

Programs

Formula

a(n) = A158648(n)*30 + 17. - Ray Chandler, Apr 07 2009
Intersection of A030432 and A007528. - Ray Chandler, Apr 07 2009
a(n) = A141860(n+1). - Zak Seidov, Apr 15 2015

Extensions

Extended by Ray Chandler, Apr 07 2009

A111175 Numbers n such that 30*n + 1 is prime.

Original entry on oeis.org

1, 2, 5, 6, 7, 8, 9, 11, 14, 18, 19, 20, 21, 22, 23, 25, 27, 33, 34, 35, 39, 40, 41, 43, 44, 46, 49, 51, 54, 58, 60, 61, 62, 65, 67, 71, 72, 74, 75, 76, 77, 78, 79, 84, 85, 89, 91, 93, 95, 99, 100, 102, 104, 106, 109, 110, 111, 112, 113, 117, 118, 119, 121, 123, 131, 134, 135
Offset: 1

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Author

Parthasarathy Nambi, Oct 21 2005

Keywords

Comments

Encoded primes with LSD 1 and (SOD-1)/3 integer, (LSD, least significant digit; SOD, sum of digits). Divide any such number by 30, if the whole number portion of the quotient is in the sequence, the number is prime. Example: 2671, with LSD 1 and (SOD-1)/3 = 2 (integer); Then 2671/30 = 89.033, or 89, which is in the sequence, and thus 2671 is prime. - Ki Punches, Mar 18 2009

Examples

			If n=99 then 30*n + 1 = 2971 (prime).
		

Crossrefs

Programs

Formula

a(n) = (A132230(n) - 1)/30 = Floor[A132230(n)/30]. - Chandler

Extensions

Extended by Ray Chandler, Apr 07 2009

A158806 Numbers n such that 30*n + 19 is prime.

Original entry on oeis.org

0, 2, 3, 4, 6, 7, 11, 12, 13, 14, 16, 20, 23, 24, 25, 27, 28, 30, 33, 34, 35, 37, 41, 42, 46, 47, 48, 49, 51, 52, 53, 55, 56, 58, 59, 62, 66, 67, 69, 72, 74, 75, 79, 84, 88, 89, 90, 91, 100, 101, 102, 103, 105, 107, 108, 110, 115, 116, 117, 118, 123, 124, 125, 129, 130
Offset: 1

Views

Author

Ki Punches, Mar 27 2009

Keywords

Comments

Encoded primes with LSD 9, (SOD-1)/3 integer, (LSD, least significant digit; SOD, sum of digits). Divide any such number by 30, if the whole number portion of the quotient is in the sequence, the number is prime.

Examples

			Example: 3019, with LSD 9, (SOD-1)/3 integer; Then 3019/30 = 100.633, or 100, which is in the sequence, thus 3019 is prime.
		

Crossrefs

Programs

Formula

a(n) = (A132234(n) - 19)/30 = Floor[A132234(n)/30]. - Chandler

Extensions

Edited by Ray Chandler, Apr 07 2009

A158573 Numbers k such that 30*k + 7 is prime.

Original entry on oeis.org

0, 1, 2, 3, 4, 5, 9, 10, 11, 12, 13, 15, 16, 18, 19, 20, 24, 25, 26, 29, 30, 31, 32, 33, 36, 37, 41, 43, 44, 48, 52, 53, 54, 55, 58, 59, 62, 66, 67, 71, 76, 78, 79, 81, 82, 85, 87, 88, 89, 90, 92, 93, 95, 96, 97, 101, 102, 106, 107, 110, 115, 117, 118, 120, 121, 123, 124, 128
Offset: 1

Views

Author

Ki Punches, Mar 21 2009

Keywords

Comments

Encoded primes with LSD 7 and (SOD-1)/3 integer, (LSD, least significant digit; SOD, sum of digits). Divide any such number by 30, if the whole number portion of the quotient is in the sequence, the number is prime.

Examples

			Example: 3877, with LSD 7 and (SOD-1)/3 = 23 (integer); Then 3877/30 = 129.233, or 129, which is in the sequence, and thus 3877 is prime.
		

Crossrefs

Programs

Formula

a(n) = (A132231(n) - 7)/30 = floor(A132231(n)/30). - Ray Chandler, Apr 07 2009
a(n) ~ (4/15) n log n. - Charles R Greathouse IV, Mar 07 2016

Extensions

Edited by Ray Chandler, Apr 07 2009

A158614 Numbers n such that 30*n + 11 is prime.

Original entry on oeis.org

0, 1, 2, 3, 4, 6, 8, 9, 10, 13, 14, 15, 16, 17, 21, 23, 25, 27, 29, 30, 31, 32, 34, 35, 36, 38, 39, 43, 45, 48, 49, 50, 52, 53, 57, 60, 62, 63, 64, 69, 70, 71, 78, 79, 80, 81, 84, 86, 87, 90, 91, 93, 95, 100, 101, 106, 107, 108, 112, 115, 116, 119, 122, 123, 125, 127, 128
Offset: 1

Views

Author

Ki Punches, Mar 22 2009, Mar 29 2009

Keywords

Comments

Encoded primes with LSD 1 and (SOD-1)/3 non-integer, (LSD, least significant digit; SOD, sum of digits). Divide any such number by 30, if the whole number portion of the quotient is in the sequence, the number is prime.

Examples

			Example: 3191, with LSD 1 and (SOD-1)/3 = 4.33 (non-integer); Then 3191/30=106.367, or 106 which is in the sequence, thus 3191 is prime.
		

Crossrefs

Programs

Formula

a(n) = (A132232(n) - 11)/30 = floor(A132232(n)/30). - Ray Chandler, Apr 07 2009

Extensions

Edited by Ray Chandler, Apr 07 2009

A158746 Numbers n such that 30*n + 13 is prime.

Original entry on oeis.org

0, 1, 2, 3, 5, 6, 7, 9, 10, 12, 14, 15, 17, 20, 21, 22, 24, 27, 28, 29, 34, 35, 36, 37, 38, 40, 43, 47, 48, 49, 51, 55, 56, 57, 58, 59, 62, 64, 66, 68, 69, 70, 71, 73, 76, 79, 82, 83, 86, 89, 90, 93, 94, 98, 105, 108, 110, 111, 112, 114, 115, 119, 120, 121, 122, 124, 126, 127
Offset: 1

Views

Author

Ki Punches, Mar 25 2009

Keywords

Comments

Encoded primes with LSD 3, (SOD-1)/3 integer, (LSD, least significant digit; SOD, sum of digits). Divide any such number by 30, if the whole number portion of the quotient is in the sequence, the number is prime.

Examples

			Example: 3163, with LSD 3 and (SOD-1)/3 = 4 (integer); Then 3163/30 = 105.433, or 105 which is in the sequence, thus 3163 is prime.
		

Crossrefs

Programs

Formula

a(n) = (A132233(n) - 13)/30 = Floor[A132233(n)/30]. - Chandler

Extensions

Edited by Ray Chandler, Apr 07 2009

A158791 Numbers n such that 30*n + 23 is prime.

Original entry on oeis.org

0, 1, 2, 3, 5, 7, 8, 9, 11, 12, 14, 16, 18, 19, 21, 22, 24, 25, 28, 31, 32, 33, 36, 38, 39, 40, 42, 45, 47, 49, 50, 51, 52, 53, 57, 60, 63, 65, 66, 68, 71, 73, 74, 75, 77, 79, 80, 84, 87, 88, 89, 91, 94, 96, 98, 100, 102, 106, 110, 113, 117, 119, 120, 126, 127, 128, 130, 133
Offset: 1

Views

Author

Ki Punches, Mar 26 2009

Keywords

Comments

Encoded primes with LSD 3 and (SOD-1)/3 non-integer, (LSD, least significant digit; SOD, sum of digits). Divide any such number by 30, if the whole number portion of the quotient is in the sequence, the number is prime.

Examples

			Example: 3623, with LSD 3 and (SOD-1)/3 non-integer; Then 3623/30 = 120.766, or 120, which is in the sequence, thus 3623 is prime.
		

Crossrefs

Programs

Formula

a(n) = (A132235(n) - 23)/30 = Floor[A132235(n)/30]. - Chandler

Extensions

Edited by Ray Chandler, Apr 07 2009

A158850 Numbers n such that 30*n + 29 is prime.

Original entry on oeis.org

0, 1, 2, 4, 5, 7, 8, 11, 12, 13, 14, 15, 16, 18, 19, 21, 23, 26, 27, 30, 33, 34, 36, 40, 41, 42, 43, 46, 47, 49, 51, 53, 56, 62, 64, 65, 67, 68, 69, 70, 76, 77, 79, 81, 84, 85, 86, 89, 90, 92, 93, 95, 96, 97, 98, 99, 102, 103, 106, 109, 110, 111, 112, 114, 117, 121, 123, 125
Offset: 1

Views

Author

Ki Punches, Mar 28 2009

Keywords

Comments

Encoded primes with LSD 9 and (SOD-1)/3 non-integer, (LSD, least significant digit; SOD, sum of digits). Divide any such number by 30, if the whole number portion from the quotient is in the sequence, the number is prime.

Examples

			Example: 3209 with LSD 9 and (SOD-1)/3 non-integer; Then 3209/30 = 106.966, or 106, which is in the sequence, thus 3209 is prime.
		

Crossrefs

Programs

Formula

a(n) = (A132236(n) - 29)/30 = Floor[A132236(n)/30]. - Chandler

Extensions

Edited by Ray Chandler, Apr 07 2009

A089161 Numbers k such that 30*k + 17 and 30*k + 19 are twin primes.

Original entry on oeis.org

0, 3, 4, 6, 7, 11, 20, 27, 28, 42, 47, 49, 53, 55, 56, 59, 62, 66, 67, 69, 74, 75, 88, 89, 105, 108, 115, 117, 118, 125, 130, 137, 138, 140, 144, 150, 151, 154, 159, 165, 180, 182, 188, 195, 206, 227, 231, 237, 243, 248, 249, 251, 258, 262, 269, 279, 284, 286, 287
Offset: 1

Views

Author

Pierre CAMI, Dec 06 2003

Keywords

Examples

			3 is a term since 30*3 + 17 = 107, 30 * 3 + 19 = 109, and (107, 109) are twin primes.
		

Crossrefs

Intersection of A158648 and A158806.
Cf. A001097 (twin primes).

Programs

  • Maple
    a:=proc(n) if isprime(30*n+17)=true and isprime(30*n+19)=true then n else fi end: seq(a(n),n=0..400); # Emeric Deutsch, Jun 13 2005
  • Mathematica
    Select[Range[0, 300], And @@ PrimeQ[30# + {17, 19}] &] (* Amiram Eldar, Jan 27 2020 *)

Extensions

More terms from Emeric Deutsch, Jun 13 2005
Showing 1-9 of 9 results.