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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A067376 Smallest integer expressible as the sum of (at least two) consecutive primes in n ways.

Original entry on oeis.org

5, 36, 240, 311, 16277, 130638, 218918, 9186778, 274452156, 4611108324, 12941709050
Offset: 1

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Author

Patrick De Geest, Feb 04 2002

Keywords

Comments

a(10)-a(11) found by Wilfred Whiteside in 2007 (see Rivera link). - Michael S. Branicky, Jul 27 2022

Examples

			In n=7 ways: 218918 = (#12,18199) (#16,13619) (#22,9851) (#28,7691) (#38,5623) (#46,4561) (#62,3301).
		

Crossrefs

Extensions

Offset corrected and a(8)-a(9) from Donovan Johnson, Mar 14 2010
a(10) confirmed and a(10)-a(11) entered by Michael S. Branicky, Jul 27 2022

A163246 Squares which can be represented as the sum of consecutive primes in more than one way.

Original entry on oeis.org

36, 100, 576, 841, 961, 1764, 1849, 2209, 2304, 7056, 22801, 24649, 25600, 30276, 31684, 32400, 36481, 39601, 40000, 47524, 48400, 48841, 57600, 58081, 66564, 69169, 69696, 76729, 77284, 80089, 85849, 93636, 94864, 96721, 112896, 119716, 128164, 134689, 138384, 140625, 142884, 147456
Offset: 1

Views

Author

Gaurav Kumar, Jul 23 2009

Keywords

Examples

			6^2 = 36 = 5 + 7 + 11 + 13 = 17 + 19.
		

Crossrefs

Formula

{ A000290 } intersect { A034707 }.
{ A000290 } intersect { A050936 }.
k^2 such that A084143(k^2) > 1. - Georg Fischer, Jul 08 2022

Extensions

Offset corrected by Arkadiusz Wesolowski, Mar 28 2012
Duplicate 2304 removed and some missing terms inserted by Georg Fischer, Jul 08 2022

A309770 Numbers that are sums of one or more consecutive primes in more than one way.

Original entry on oeis.org

5, 17, 23, 31, 36, 41, 53, 59, 60, 67, 71, 72, 83, 90, 97, 100, 101, 109, 112, 119, 120, 127, 131, 138, 139, 143, 152, 173, 180, 181, 187, 197, 199, 204, 210, 211, 221, 223, 228, 233, 240, 251, 258, 263, 269, 271, 276, 281, 287, 300, 304, 311, 323, 330, 331, 340, 349
Offset: 1

Views

Author

Ilya Gutkovskiy, Aug 16 2019

Keywords

Comments

Contains A067372 as a subsequence.

Examples

			5 is in the sequence because it can be written as either 5 or 2 + 3.
36 is the sequence because it can be written as either 5 + 7 + 11 + 13 or 17 + 19.
		

Crossrefs

Programs

  • Maple
    N:= 1000: # for terms <= N
    P:= select(isprime, [2, seq(i,i=3..N,2)]):
    S:= [0,op(ListTools:-PartialSums(P))]:
    V:= Vector(N):
    for i from 1 to nops(S) do
      for j from i-1 to 1 by -1 do
        v:= S[i]-S[j];
        if v > N then break fi;
        V[v]:= V[v]+1;
    od od:
    select(t -> V[t]>1, [$1..N]); # Robert Israel, Aug 22 2019

Formula

A054845(a(n)) > 1.
Previous Showing 11-13 of 13 results.