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.

A340771 Numbers which are the sum of some number of consecutive prime squares.

Original entry on oeis.org

4, 9, 13, 25, 34, 38, 49, 74, 83, 87, 121, 169, 170, 195, 204, 208, 289, 290, 339, 361, 364, 373, 377, 458, 529, 579, 628, 650, 653, 662, 666, 819, 841, 890, 940, 961, 989, 1014, 1023, 1027, 1179, 1348, 1369, 1370, 1469, 1518, 1543, 1552, 1556, 1681, 1731, 1802, 1849
Offset: 1

Views

Author

Michel Marcus, Jan 20 2021

Keywords

Examples

			The initial terms are 2^2, 3^2, 2^2+3^2, 5^2, 3^2+5^2, ...
		

Crossrefs

Programs

  • Maple
    N:= 10000: # for terms <= N
    PS:= [0,seq(ithprime(i)^2,i=1..numtheory:-pi(floor(sqrt(N))))]:
    SPS:= ListTools:-PartialSums(PS):
    sort(convert(select(`<=`,{seq(seq(SPS[t]-SPS[s],s=1..t-1),t=2..nops(SPS))},N),list)); # Robert Israel, Jan 20 2021
  • PARI
    lista(nn) = {my(list = List(), ip = primepi(nn), vp = primes(ip)); for(i=1, ip, my(s=vp[i]^2); listput(list, s); for (j=i+1, ip, s += vp[j]^2; if (s >vp[ip]^2, break); listput(list, s););); Vec(vecsort(list,,8));} \\ Michel Marcus, Jan 20 2021