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.

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A357890 a(n) = (A022013(n) - 173)/210.

Original entry on oeis.org

422, 1355, 4074, 5460, 31242, 329316, 353648, 1038255, 1246060, 1440679, 4593664, 6382389, 6669205, 6773694, 8748381, 9343041, 10085055, 10711252, 10819136, 12181959, 12804411, 13683806, 14044105, 15616253, 19232028, 20795482, 21014272, 25076295, 26366476, 27457318
Offset: 1

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Author

Hugo Pfoertner, Nov 18 2022

Keywords

Comments

Linear conversion of the initial members of prime octuplets of type p + {0, 6, 8, 14, 18, 20, 24, 26}.
Numbers k such that 210*k+173, 210*k+179, 210*k+181, 210*k+187, 210*k+191, 210*k+193, 210*k+197, and 210*k+199 are all primes. - Jianing Song, Nov 18 2022

Crossrefs

Cf. A182393 (similar for type p + {0, 2, 6, 8, 12, 18, 20, 26}).
Cf. A145315 (minus 1, similar for type p + {0, 2, 6, 12, 14, 20, 24, 26}).
Subsequence of A357889.

A375344 First term p1 of octuplets of consecutive prime numbers pi with given successive gaps pi-p1, i=2, ...,8 (6, 8, 18, 24, 30, 36, 38).

Original entry on oeis.org

233, 2721413, 154670903, 200559053, 232777673, 273788363, 299267663, 459117353, 527326403, 1015923113, 1563572243, 1688692763, 2426018723, 2918492243, 3743134523, 4445599853, 4458163943, 4697619593, 5493835013, 5546977823, 5930389313, 6131660663, 6470661143, 7598587943
Offset: 1

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Author

René-Louis Clerc, Aug 12 2024

Keywords

Comments

The choice of successive gaps (6, 8, 18, 24, 30, 36, 38) is such that the sum of the eight prime numbers beginning with 233 is 2024. The next year being the sum of analogous octuplet is 21771464 (21772nd millenium).

Examples

			233, 239, 241, 251, 257, 263, 269, 271 (sum = 2024).
2721413, 2721419, 2721421, 2721431, 2721437, 2721443, 2721449, 2721451 (sum = 21771464).
		

Crossrefs

Programs

  • PARI
    uplet(p)= {n=0;for(i=p, p+38, if(isprime(i), n+=1));n}
    octo(m)={for(p=3,p=10^m,if(isprime(p) && isprime(p+6) && isprime(p+8) && isprime(p+18) && isprime(p+24) && isprime(p+30) && isprime(p+36) && isprime(p+38) && uplet(p)==8,print1(p,", ")))}
    listocto(p1)=print1(p1,", ", p1+6,", ", p1+8,", ", p1+18,", ", p1+24,", ", p1+30,", ", p1+36", ", p1+38)
Previous Showing 41-42 of 42 results.