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 1-3 of 3 results.

A174519 Sum of 3 consecutive primes and of all composite numbers in-between.

Original entry on oeis.org

14, 25, 56, 70, 98, 112, 140, 264, 243, 297, 396, 280, 308, 528, 689, 513, 567, 726, 490, 675, 858, 924, 1350, 1235, 700, 728, 742, 770, 2242, 2318, 1452, 1215, 1859, 1885, 1377, 2041, 1782, 1848, 2249, 1593, 2405, 2431, 1358, 1372, 3060, 5275, 3723, 1582
Offset: 1

Views

Author

Vladimir Joseph Stephan Orlovsky, Mar 21 2010

Keywords

Comments

2+3+4+5=14, 3+4+5+6+7=25, 5+6+7+8+9+10+11=56, ..

Crossrefs

Cf. A034962, A054265, A174518

Programs

  • Mathematica
    f[n_,x_]:=n*x+x*(x+1)/2;Table[Prime[n]+f[Prime[n],Prime[n+2]-Prime[n]-1]+Prime[n+2],{n,5!}]
sm[{a_,b_,c_}]:=(c-a+1) (a+c)/2; sm/@Partition[Prime[Range[50]],3,1] (* Harvey P. Dale, Mar 11 2012 *)

A174520 Sum of all composite numbers in-between prime numbers p(n) and p(n+2).

Original entry on oeis.org

4, 10, 33, 39, 57, 63, 81, 193, 160, 200, 287, 159, 177, 385, 530, 340, 380, 527, 279, 452, 623, 673, 1081, 948, 399, 417, 423, 441, 1893, 1947, 1057, 808, 1434, 1446, 920, 1570, 1295, 1345, 1730, 1060, 1854, 1866, 777, 783, 2453, 4642, 3062, 903, 921, 1873
Offset: 1

Views

Author

Vladimir Joseph Stephan Orlovsky, Mar 21 2010

Keywords

Comments

2_3_4_5 -> 4, 3_4_5_6_7 -> 4+6=10, 5_6_7_8_9_10_11 -> 6+8+9+10=33, ..

Crossrefs

Cf. A034962, A054265, A174518, A174519

Programs

  • Mathematica
    f[n_,x_]:=n*x+x*(x+1)/2;Table[f[Prime[n],Prime[n+2]-Prime[n]-1]-Prime[n+1],{n,5!}]

A174521 Primes that are the sum of all composite numbers in-between prime numbers p(n) and p(n+2).

Original entry on oeis.org

193, 673, 1873, 2207, 2833, 4391, 3023, 8209, 5903, 8999, 6047, 9643, 7537, 19843, 10273, 29399, 11953, 12433, 20879, 35999, 36241, 23761, 23831, 24907, 20353, 32401, 33403, 22367, 34129, 57367, 49123, 74311, 51197, 40037, 42773, 71399
Offset: 1

Views

Author

Vladimir Joseph Stephan Orlovsky, Mar 21 2010

Keywords

Comments

20+21+22+24+25+26+27+28=193,..

Links

Crossrefs

Cf. A034962, A054265, A174518, A174519, A174520

Programs

  • Mathematica
    f[n_,x_]:=n*x+x*(x+1)/2;Select[Table[f[Prime[n],Prime[n+2]-Prime[n]-1]-Prime[n+1],{n,6!}],PrimeQ[ # ]&]
Select[Table[Total[Select[Range[Prime[n],Prime[n+2]],CompositeQ]],{n,1000}],PrimeQ] (* Harvey P. Dale, May 13 2017 *)
Showing 1-3 of 3 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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