%I #16 Jun 26 2022 11:39:20

%S 1,13,361,18589,2293369,392915461,114454369129,41578647715669,

%T 22089188627685001,18626778064527922741,17942190650501641587001,

%U 24603083510737933160021269,41412850736015889039729489289,76664929233749755566050236079461

%N Numerator of Sum_{i=1..n} 1/p(i)^2, p(i) = i-th prime.

%H Michael S. Branicky, <a href="/A061015/b061015.txt">Table of n, a(n) for n = 1..195</a>

%F a(1) = 1; a(n) = a(n-1)*p(n)^2+(p(1)*...*p(n-1))^2. - _Zak Seidov_, Sep 28 2002

%p summ := 0: for n from 1 to 100 do if (isprime(n)) then summ := summ + 1/n^2; printf("%d,", numer(summ)); #printf("%d,", denom(summ)); end if; od; evalf(summ);

%t Numerator[Accumulate[1/Prime[Range[13]]^2]] (* _Jayanta Basu_, Jul 14 2013 *)

%o (Python)

%o from sympy import prime

%o from fractions import Fraction

%o from itertools import accumulate, count, islice

%o def A061015gen(): yield from map(lambda x: x.numerator, accumulate(Fraction(1, prime(k)**2) for k in count(1)))

%o print(list(islice(A061015gen(), 20))) # _Michael S. Branicky_, Jun 26 2022

%Y Cf. A000040, A075986, A075987.

%K easy,nonn,frac

%O 1,2

%A Winston C. Yang (winston(AT)cs.wisc.edu), May 21 2001

%E a(14) and beyond from _Michael S. Branicky_, Jun 26 2022