A065408 Squares whose digits sum to a prime.

16, 25, 49, 256, 289, 625, 676, 784, 841, 1024, 1156, 1369, 1444, 1600, 1936, 2209, 2401, 2500, 2704, 2809, 3136, 3721, 3844, 4096, 4225, 4900, 5329, 6241, 6724, 6889, 7921, 8281, 9604, 11236, 11449, 11881, 13225, 13456, 13924, 14161, 15625, 16129

Offset

1,1

Links

Harry J. Smith, Table of n, a(n) for n = 1..1000

Mathematica

Select[Range[1000]^2, PrimeQ[Total[IntegerDigits[#]]]&]

Prog

(PARI) SumD(x)= { local(s=0); while (x>9, s+=x-10*(x\10); x\=10); return(s + x) } { n=0; for (m=1, 10^9, if (isprime(SumD(m^2)), write("b065408.txt", n++, " ", m^2); if (n==1000, return)) ) } \\ Harry J. Smith, Oct 18 2009

Crossrefs

Cf. A000290, A007953, A107289.

Sequence in context: A002644 A118489 A110922 * A112392 A109685 A188826

Adjacent sequences: A065405 A065406 A065407 * A065409 A065410 A065411

Keyword

base,easy,nonn

Author

Jason Earls, Nov 22 2001

Status

approved