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A225741
Primes p such that the sum of the squares of the digits of p plus p is the square of a prime.
1
71, 1997, 2707, 3407, 32647, 143509, 177131, 196073, 273433, 292517, 360977, 418447, 477341, 578789, 981769, 1066867, 1079269, 1125559, 1394539, 2024831, 2246851, 2679493, 3659401, 3736351, 4932637, 5148233, 5479939, 5726257, 5726321, 5755051, 7070093, 7091339, 7789289, 8082419
OFFSET
1,1
LINKS
Charles R Greathouse IV, Table of n, a(n) for n = 1..3016
EXAMPLE
71 is a member since 71+(7^2+1^2)=11^2, 1997 is a member since 1997+(1^2+9^2+9^2+7^2)= 47^2.
PROG
(PARI) ssd(n)=my(d=digits(n)); sum(i=1, #d, d[i]^2)
is(n)=my(t); issquare(ssd(n)+n, &t) && isprime(t) && isprime(n) \\ Charles R Greathouse IV, Aug 13 2013
CROSSREFS
Sequence in context: A198449 A093271 A201608 * A049295 A017787 A332665
KEYWORD
nonn,base,less
AUTHOR
Will Gosnell, Aug 13 2013
EXTENSIONS
a(5)-a(34) from Charles R Greathouse IV, Aug 13 2013
STATUS
approved