A373171 a(1) = 1; for n >= 2, a(n) = noz(a(n-1) + 3*n - 2), where noz(n) = A004719(n).

1, 5, 12, 22, 35, 51, 7, 29, 54, 82, 113, 147, 184, 224, 267, 313, 362, 414, 469, 527, 588, 652, 719, 789, 862, 938, 117, 199, 284, 372, 463, 557, 654, 754, 857, 963, 172, 284, 399, 517, 638, 762, 889, 119, 252, 388, 527, 669, 814, 962, 1113, 1267, 1424, 1584

Offset: 1

Author

Paolo Xausa, May 28 2024

Keywords

• nonn
• base
• easy

Comments

Zeroless analog of the positive pentagonal numbers.

Links

• Paolo Xausa, Table of n, a(n) for n = 1..10000

Crossrefs

Row n = 5 of A373169.

Cf. A000326, A004719, A243658, A370812, A373172.

Programs

Mathematica

noz[n_] := FromDigits[DeleteCases[IntegerDigits[n], 0]];
Block[{n = 1}, NestList[noz[++n*3 - 2 + #] &, 1, 100]]

PARI

noz(n) = fromdigits(select(sign, digits(n))); \\ A004719
lista(nn) = my(va=vector(nn)); for (n=1, nn, va[n] = if (n==1, 1, noz(va[n-1] + 3*n - 2))); va; \\ Michel Marcus, Jun 03 2024