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A165493 Primes p where the digital sum of p^2 is equal to 19. 7
17, 37, 53, 73, 89, 107, 109, 127, 181, 199, 269, 271, 379, 503, 521, 557, 701, 739, 1009, 1061, 1097, 1151, 1171, 1439, 1511, 1601, 1619, 1747, 1801, 1871, 2251, 3169, 3259, 3329, 3347, 3511, 3761, 3851, 3889, 4051, 4139, 4519, 4751, 4951, 5003, 5021, 5849 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..215

FORMULA

{A000040(i) : A123157(i) = 19} [R. J. Mathar, Sep 29 2009]

EXAMPLE

17 is in the sequence because 17^2=289 and 2+8+9=19.

1801 is in the sequence because 1801^2=3243601 and 3+2+4+3+6+0+1=19.

MAPLE

A007953 := proc(n) add(d, d=convert(n, base, 10)) ; end:

A123157 := proc(n) A007953((ithprime(n))^2) ; end:

for n from 1 to 100000 do if A123157(n) = 19 then printf("%d, ", ithprime(n)) ; fi; od: # R. J. Mathar, Sep 29 2009

MATHEMATICA

Select[Prime[Range[800]], Total[IntegerDigits[#^2]]== 19&] (* Vincenzo Librandi, Jun 24 2013 *)

PROG

(MAGMA) [p: p in PrimesUpTo(6000) | &+Intseq(p^2) eq 19]; // Bruno Berselli, Jun 24 2013

CROSSREFS

Sequence in context: A217195 A177835 A075698 * A339531 A295338 A059425

Adjacent sequences:  A165490 A165491 A165492 * A165494 A165495 A165496

KEYWORD

nonn,base

AUTHOR

Vincenzo Librandi, Sep 21 2009

EXTENSIONS

More terms from R. J. Mathar, Sep 29 2009

STATUS

approved

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Last modified March 7 10:38 EST 2021. Contains 341869 sequences. (Running on oeis4.)