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A228195 Primes with the property that the sum of the cubes of their digits plus the prime equals another prime squared. 2
17, 2897, 11471, 15527, 19949, 26693, 26783, 72467, 78041, 142757, 159209, 216791, 350747, 366917, 672593, 725891, 775007, 1187939, 1529153, 1659737, 2024093, 2035097, 2035349, 2105231, 2127761, 2598929, 2645933, 2917799, 3322439, 3497993, 3970643, 4042697, 4067513, 4280051, 4329257, 4464017, 5839397 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

EXAMPLE

17 is a term since (1^3 + 7^3) + 17 = 19^2.

2897 is a term since (2^3 + 8^3 + 9^3 + 7^3) + 2897 = 67^2.

11471 is a term since (1^3 + 1^3 + 4^3 + 7^3 + 1^3) + 11471 = 109^2.

PROG

(PARI) is(n)=my(d=digits(n), k); issquare(sum(i=1, #d, d[i]^3)+n, &k) && isprime(k) && isprime(n) \\ Charles R Greathouse IV, Jun 16 2014

(PARI) searchdigit(n)=my(v=List(), N1=10^(n-1), N2=10^n, t=729*n, d, k, p2); forprime(p=sqrtint(N1)+1, sqrtint(N2+t), p2=p^2; forprime(q=max(N1, p2-t+2), min(N2, p2-2), d=digits(q); if(sum(i=1, #d, d[i]^3)+q==p2, listput(v, q)))); Vec(v)

v=[]; for(n=1, 9, v=concat(v, searchdigit(n))); v \\ Charles R Greathouse IV, Jun 16 2014

CROSSREFS

Sequence in context: A198594 A138199 A125000 * A032909 A239165 A329168

Adjacent sequences:  A228192 A228193 A228194 * A228196 A228197 A228198

KEYWORD

nonn,base,less

AUTHOR

Will Gosnell, Aug 15 2013

EXTENSIONS

a(10)-a(37) from Charles R Greathouse IV, Jun 16 2014

STATUS

approved

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Last modified December 9 13:50 EST 2019. Contains 329877 sequences. (Running on oeis4.)