A166503 -id:A166503 - cp's OEIS frontend

A038692 Square numbers that are concatenations of two or more prime numbers.

25, 225, 289, 361, 529, 729, 2401, 2601, 2809, 4761, 5329, 5929, 7225, 7569, 11449, 11881, 13225, 15129, 19881, 21609, 22801, 23409, 24649, 25281, 26569, 27225, 29241, 29929, 31329, 32761, 34969, 36481, 39601, 47961, 52441, 53361, 54289, 55225, 57121, 58081

Offset: 1

Jeff Burch

Jinyuan Wang, Table of n, a(n) for n = 1..1000

Cf. A166503 (the square roots).

ric[d_] := PrimeQ@ FromDigits@ d || AnyTrue[ TakeDrop[d, #] & /@ Range[ Length[d] - 1], #[[2,1]] > 0 && PrimeQ@ FromDigits@ #[[1]] && ric@ #[[2]] &]; ok[n_] := If[ EvenQ[n] && Mod[n, 10] != 2, False, ric@ IntegerDigits@ n]; Select[ Range[300]^2, ok] (* Giovanni Resta, Mar 16 2020 *)

forstep(n=1, 300, 2, is_A152242(n^2) & print1(n^2, ", ")) \\ M. F. Hasler, Mar 19 2012

A038692(n) = A166503(n)^2. As a set, A038692 = A000290 intersection A152242 = A016754 intersection A152242. - M. F. Hasler, Mar 19 2012

Edited by N. J. A. Sloane, Oct 18 2009, incorporating corrections from M. F. Hasler and Zak Seidov.

A165631 Numbers whose cube is a concatenation of primes, i.e., in A152242.

Original entry on oeis.org

3, 7, 9, 11, 13, 15, 17, 18, 27, 28, 29, 31, 33, 38, 39, 45, 47, 48, 49, 53, 55, 58, 59, 61, 63, 68, 71, 73, 75, 83, 85, 88, 91, 95, 98, 103, 108, 111, 113, 117, 121, 125, 127, 131, 133, 135, 137, 138, 148, 153, 157, 159, 161, 163, 167, 168, 173, 175, 177, 178, 179

Offset: 1

Zak Seidov and M. F. Hasler, Oct 16 2009

Cf. A038692, A019549, A105184, A166503.

for(n=1,999, is_A152242(n^3) & print1(n", "))

Edited by Charles R Greathouse IV, Apr 24 2010

cp's OEIS Frontend

A038692 Square numbers that are concatenations of two or more prime numbers.

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