A334542 -id:A334542 - cp's OEIS frontend

A334557 Numbers m such that m = p^2 + k^2, with p > 0, where p = A007954(m) = the product of digits of m.

1, 13, 41, 61, 125, 212, 281, 613, 1156, 1424, 2225, 3232, 3316, 4113, 11125, 11281, 11525, 12816, 14913, 16317, 16441, 19125, 21284, 21625, 24128, 25216, 27521, 31525, 53125, 56116, 61321, 65161, 71325, 82116, 82217, 83521, 84313, 111812, 113125, 113625, 115336, 115681, 117125, 118372

Offset: 1

Scott R. Shannon, May 06 2020

			13 is a term as p = 1*3 = 3 and 13 = 3^2 + 2^2.
281 is a term as p = 2*8*1 = 16 and 281 = 16^2 + 5^2.
118372 is a term as p = 1*1*8*3*7*2 = 336 and 118372 = 336^2 + 74^2.

Giovanni Resta, Table of n, a(n) for n = 1..10000

Cf. A007954, A000404, A078134, A334542, A334558.

isok(m) = my(p=vecprod(digits(m))); p && issquare(m - p^2); \\ Michel Marcus, May 06 2020

A334558 Numbers m such that m^2 + p^2 = k^2, with p > 0, where p = A007954(m) = the product of digits of m.

Original entry on oeis.org

429, 437, 598, 1938, 3584, 3875, 5576, 6864, 16758, 36828, 43778, 47775, 47859, 56637, 56672, 82928, 91798, 129584, 156782, 165688, 165838, 178857, 215985, 379488, 655578, 798847, 1881576, 2893337, 3918768, 4816872, 5439798, 5829795, 7558299, 9675288, 11943887

Offset: 1

Scott R. Shannon, May 06 2020

			429 is a term as p = 4*2*9 = 72 and 429^2 + 72^2 = 189225 = 435^2.
16758 is a term as p = 1*6*7*5*8 = 1680 and 16758^2 + 1680^2 = 283652964 = 16842^2.

Giovanni Resta, Table of n, a(n) for n = 1..147 (terms < 2*10^13)

Cf. A007954, A000404, A078134, A334542, A334557.

isok(m) = my(p=vecprod(digits(m))); p && issquare(m^2 + p^2); \\ Michel Marcus, May 06 2020

cp's OEIS Frontend

A334557 Numbers m such that m = p^2 + k^2, with p > 0, where p = A007954(m) = the product of digits of m.

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